Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in Kisangani

Likilo Osundja Jérémie; Tshodi Bulanda Arsène; Lufuluabu Mpemba Alphonse; Mbohou Kouaming Aminate Nawal; Komanda Likeweke Emmanuel; Katenga Bosunga Gédéon

doi:10.12688/f1000research.161666.2

Home Browse Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in...

ALL Metrics

-

Views

-

Downloads

Get PDF

Get XML

Export

▬

✚

Research Article

Revised

Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in Kisangani

[version 2; peer review: 2 not approved]

Likilo Osundja Jérémie ¹, Tshodi Bulanda Arsène ², Lufuluabu Mpemba Alphonse ³, Mbohou Kouaming Aminate Nawal¹, Komanda Likeweke Emmanuel¹, Katenga Bosunga Gédéon¹

Likilo Osundja Jérémie ¹, Tshodi Bulanda Arsène ², [...] Lufuluabu Mpemba Alphonse ³, Mbohou Kouaming Aminate Nawal¹, Komanda Likeweke Emmanuel¹, Katenga Bosunga Gédéon¹

PUBLISHED 19 Sep 2025

Author details Author details

¹ gynécology et obstétric, University of Kisangani, Kisangani, TSHOPO, Democratic Republic of the Congo
² Gynecology and obstetric, University of MBUJIMAYI, MBUJIMAYI, Eastern Kasai, Democratic Republic of the Congo
³ Internal medecine, University of Mbujimayi, MBUJIMAYI, Eastern Kasai, Democratic Republic of the Congo

Likilo Osundja Jérémie
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Tshodi Bulanda Arsène
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Lufuluabu Mpemba Alphonse
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Mbohou Kouaming Aminate Nawal
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Komanda Likeweke Emmanuel
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Katenga Bosunga Gédéon
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

OPEN PEER REVIEW

REVIEWER STATUS

Abstract

Background

Syphilis is a cosmopolitan infection, with recent infections (primary or secondary syphilis <1 year) posing the highest risk of mother-to-child transmission. In such cases, early treatment is crucial in determining obstetric prognosis.

Objective

This study aims to present current data of syphilis in pregnant women and improve the management of syphilis in pregnant women in the city of Kisangani.

Methods

This is an analytical case-control study covering the period from July 1, 2023, to December 1, 2023. The study was conducted at Makiso Kisangani General Referral Hospital, with a study population of 290 pregnant women. A non-exhaustive sampling method was used, selecting, in the obstetrical department, a sample of 145 pregnant women diagnosed with syphilis and 145 others diagnosed with out syphilis. Data were analyzed using R software version 4.3.

Results

The most represented age group was 20 to 34 years (61.4%). The majority of pregnant women with syphilis were married (61.4%), in monogamous relationships (72.4%), and had unemployed partners (26.9%). The most common risk factors were having a partner who was a driver (OR: 3.31; p = 0.028), a trader (OR: 8.08; p <0.001), and having a history of STIs (p <0.001) or multiple sexual partners (p = 0.011). In 75% of cases, pregnancy resulted in the birth of a live fetus and 25% cases result in the birth of a died fetus.

Conclusion

Adverse pregnancy outcomes associated with syphilis could be reduced through early detection and standard treatment of syphilis for pregnant women and their husbands/sexual partners.

Keywords

Syphilis, prevalence, risk factors of syphilys in pregnancy, maternel and fetal prognosis.

Corresponding authors: Likilo Osundja Jérémie, Tshodi Bulanda Arsène, Lufuluabu Mpemba Alphonse

Competing interests: No competing interests were disclosed.

Grant information: The author(s) declared that no grants were involved in supporting this work.

Copyright: © 2025 Jérémie LO et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: Jérémie LO, Arsène TB, Alphonse LM et al. Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in Kisangani [version 2; peer review: 2 not approved]. F1000Research 2025, 14:232 (https://doi.org/10.12688/f1000research.161666.2) First published: 25 Feb 2025, 14:232 (https://doi.org/10.12688/f1000research.161666.1) Latest published: 19 Sep 2025, 14:232 (https://doi.org/10.12688/f1000research.161666.2)

Revised Amendments from Version 1

We made some minor changes to the summary. We restructured the Introduction. In the Methods section, we described the collection technique, added the diagram and operational definitions, and removed some sentences. In the Results, we removed Table 2; merged Tables 1 and 4 into Table 1, and Tables 5 and 6 into Table 3. We reorganized the Discussion.

To read any peer review reports and author responses for this article, follow the "read" links in the Open Peer Review table.

Introduction

Syphilis is a sexually transmitted disease caused by Treponema pallidum. It can also be transmitted vertically. If left untreated, syphilis can lead to complications during the second or third trimesters of pregnancy.^1,2

Vertical transmission can occur as early as the 11^th week of amenorrhea or during delivery. It occurs in 50% of cases and leads to many complications. Such as early fetal death, stillbirth, preterm birth, low birth weight, neonatal death, and congenital infection in infants.^3,4 In 2016, maternal syphilis cases were estimated to have resulted in 143,000 early fetal deaths and stillbirths, 61,000 neonatal deaths, 41,000 preterm births or low birth weight cases, and 109,000 cases of clinical congenital syphilis.⁵^,⁶

The diagnosis of syphilis is simple and its treatment less expensive and not contraindicated during pregnancy. But syphilis in pregnant women is still an underestimated public health problem. According to the WHO, 2 million women are infected with syphilis worldwide and among untreated cases there are 65% of fetal complications.^7,8

It is estimated that 2.7% of pregnant women in sub-Saharan Africa are infected with syphilis, representing more than 900,000 at-risk pregnancies each year.⁹

Despite the implementation of various guidelines to control sexually transmitted infections in the Democratic Republic of the Congo, the burden of syphilis persists. There are inconsistencies in the quality and utilization of services, which may be influenced by the knowledge of healthcare providers and pregnant women. Additionally, the prevalence of syphilis in urban and rural areas is different. Many factors such as diagnosis, treatment, frequency of visits, behavioral factors, sociodemographic and gyneco-obstetrical factors can change the burden of this disease.^10–12

Moreover, data on syphilis in the Democratic Republic of the Congo, particularly in our study area, are scarce. Therefore, this study targets to determine the prevalence of syphilis in pregnant women and its associated factors. in the city of Kisangani. The aim is to raise awareness among pregnant women about measures to prevent the adverse effects of this disease during pregnancy and to provide scientists with insights into the current syphilis rate and its most common complications among pregnant women in Kisangani.

To conduct this research, we asked the question:

What are the epidemiological aspects of syphilis among pregnant women in Kisangani?

General objective

This study aims to present current data of syphilis in pregnant women and improve the management of syphilis in pregnant women in the city of Kisangani.

Specific objectives

• To improve the management of syphilis in pregnant women in the city of Kisangani.
• To identify the risk factors for syphilis among pregnant women.
• To determine the maternal and fetal prognosis of syphilis during pregnancy.

Methods

Study population

Our study population consisted of 290 pregnant women of whom 145 were syphilis positive and 145 were syphilis negative. They were selected among pregnant women who attended the prenatal consultation service at Makiso Kisangani General Referral Hospital (HGR) during the period from July 1, 2023, to December 1, 2023. Makiso hospital is located in Kisangani city, province of Tshopo, Democratic Republic of the Congo.

Inclusion criteria

For our study, we included:

• Pregnant women admitted to and/or followed up at HGR Makiso Kisangani during the study period;
• Pregnant women who attended at least four prenatal consultations (PNCs) during their pregnancy;
• Pregnant women diagnosed with syphilis, cases, or without syphilis,control, during pregnancy confirmed by VDRL and TPHA tests; without comorbidity such as diabete, high blood pressure and heart diseases;
• Pregnant women with a PNC record and a complete medical file;
• Pregnant women who consented to screening.

Exclusion criteria

The following were excluded:

• Pregnant women who did not attend at least four PNCs during their pregnancy;
• Pregnant women with incomplete PNC records or medical files;
• Pregnant women who did not consent to screening.

Type of study

We conducted an case-control study.

Data collection technique

967 pregnant women who attended prenatal consultations at HGR Makiso Kisangani during our study period underwent a VDRL test for the diagnosis of syphilis. Those who were tested positive for the VDRL underwent a second confirmatory diagnostic test, TPHA. 165 pregnant women had confirmed positive syphilis. Only 145 consented to participate in this study. We performed a matching of 1 case to 1 control. The matching considered age (+-5 years of the age of the case), gestational groups and parity, age of pregnancy in week of amenorrhea, and type of pregnancy (see Figure 1 one page 3).

Figure 1. Flowchart of study population selection for case-control study on syphilis among pregnant women in Kisangani.

Data were collected using a pre-established data collection form, which included the following parameters:

• Age
• Marital status
• Occupation (of the pregnant woman and her spouse)
• Address
• Educational level
• Socioeconomic status
• Type of marriage
• Obstetric formula
• Gestational age
• Medical history
• Paraclinical examinations
• Newborn weight and observed anomalies at birth
• Placental weight.

Operational definitions

Nulliparity: condition of woman who has never given birth to a live baby

Primiparity: condition of woman who gives birth for the first time

Second parity: condition of woman who gives birth for the second time

Multiparity: condition of woman having more than 2 children

Primigravida: woman who is pregnant for the first time

Second-gravida: woman who is pregnant for the second time

Multigravida: woman who has been pregnant more than 2 times

Monogamy: for woman whose husband has only one wife

Polygamy: for woman whose husband has more than one wife

Statistical analysis

Data entry was performed using Google Forms, and data analysis was conducted using R software version 4.3.

Results are presented in tables within means and standard deviations calculated for quantitative variables and frequencies and percentages calculated for qualitative variables. The confidence interval (CI) is 95%. Univariate logistic regression was used to calculate the odds ratio and to identify risk factors for syphilis during pregnancy. The test was considered valid if the P value was less than 0.05.

Ethical considerations

This study was approved by the Ethics Committee of the University of Kisangani, UNIKIS/CER/024/2023 on 7th of June 2023. This study was conducted in accordance with the requirements of good clinical practices and the principles of the Helsinki Declaration of the World Medical Association, along with any subsequent relevant amendments. Consent was obtained from the authorities of the participating institutions, and measures were taken to ensure that no information allowing patient identification was collected. Data were collected using code for each pregnant woman instead of the name. We did not publish data that could identify the participants.

All participants have given their consent to participate to this study by signing the written document, the consent form. We had assent of the pregnant minors and the consent of their owners.

Consent to publish

The participants also gave their consent for their data to be published. Our data collection was done anonymously. We have taken all measures not to publish any data that could facilitate the identification of participants.

Results

Sociodemographic characteristics and gynecological antecedent of pregnant women with syphilis

The table below presents the cases of syphilis according to the sociodemographic characteristics of the pregnant women.

Table 1. Distribution of syphilis cases by sociodemographic characteristics and gynecological antecedent.

Sociodemographic characteristics	Case number (N = 145)	%	Control number (N = 145)	%
Age (year)
< 20	17	11.7	16	11.0
20 à 34	89	61.4	90	62.1
≥ 35	39	26.9	39	26.9
Marital status
Married	89	61.4	100	69
Single	56	38.6	45	31.0
Type of marriage
Monogamic	63	72.4	73	50.4
Polygamic	24	27.6	27	18.6
Occupation
House keeper	32	22.1	28	19.3
Student	29	20.0	23	15.9
Unemployed	29	20.0	31	21.4
Trader	23	15.9	21	14.5
State agent	17	11.7	25	17.2
Private sector employee	15	10.3	17	11.7
Husband occupation
Unemployed	39	26.9	26	17.9
Trader	38	26.2	10	6.9
State agent	29	20.0	30	20.7
Driver	17	11.7	10	6.9
Student	14	9.7	7	4.8
Teacher	8	5.5	17	11.7
Adress
Mangobo	67	46.2	37	25.5
Tshopo	54	37.2	33	22.8
Makiso	24	16.6	39	28.9
Lubunga	0	0	6	4.1
Kisangani	0	0	11	7.6
Kabondo	0	0	19	13.1
Level of education
Elementary school	43	29.7	24	16.6
High school	67	46.2	67	46.2
University	35	24.1	54	37.2
Socio-economic level
High	34	23.5	39	26.9
Middle	67	46.2	75	51.7
Low	44	30.3	31	21.4
Story of sexual transmitted infection	77(n)	53.1	41(n)	27.6
Syphilis	31	40.3	12	29.3
Gonorrhea	20	26	16	39.0
Condyloma	13	16.9	7	17.1
Trichomonas vaginalis	13	16.9	6	14.6
Notion of more than one sexual partner	63	43.5	42	30
Concept of male condom use	41	28.3	41	28.3
Anti-retroviral treatment	37	25.5	22	15.2

The most represented age group was between 20 and 34 years (61.4%). Married pregnant women in a monogamous relationship accounted for 72.4%. Housewives made up 22.1% of the study population, while women whose spouses were unemployed were also the most represented. Additionally, women with a secondary level of education constituted 46.2%. Pregnant women with a notion of sexually transmitted infection were the most represented with a frequency of 53.1%. Pregnant women who had a history of syphilis were the most affected with a frequency of 40.3% (see Table 1 on pages 4-5).

Distribution of syphilis cases according to obstetrical

The table below presents syphilis cases by obstetric history.

Table 2. Distribution of cases by obstetrical history.

Obstetrical histories	Cases number (N = 145)	%
Gestational age (in weeks of amenorrhea)
15-25	59	40.7
26-37	86	59.3
Pregnancy type
Monofetal	90	62.1
Twin	41	28.3
Multiple	14	9.7
Gesture
Primigravida	5	3.5
Second-gesture	19	13.1
Multigesture	121	83.5
Parity
Nulliparous	14	9.7
Primiparous	37	25.5
Second-parous	42	29.0
Multiparous	52	35.9
Abortion
0	96	66.2
1	33	22.8
2	8	5.5
3	8	5.5
Child death story in the family
0	101	69.7
1	44	30.3
Past route of delivery
Cesarean	50	34.5
Vaginnaly	110	75.9

It emerges from this table that: Pregnant women with a gestational age between 26 and 37 weeks were 59.3%; 62.1% of pregnant women with syphilis had a singleton pregnancy; 83.5% were multi-procedure, 75.9% of pregnant women with syphilis had given birth vaginally in the past (see Table 2 on page 6).

Distribution of syphilis cases according to syphilis treatment, Pregnancy outcome and fetal prognosi

The table below presents syphilis cases that received treatment for syphilis and the outcome of the pregnancy and fetal prognosis according to the cases of syphilis.

Table 3. Presentation of cases by syphilis treatment received, pregnancy outcome, type of abortion, fetal prognosis.

	Fréquency (N=145)	Percentage
Syphilis treatment
Yes	96	66.2
No	49	33.8
Pregnancy outcome
Abortion	29	20.0
Death in utero	29	20.0
Premature birth	37	25.5
Full-term delivery	50	34.4
Abortion type
Early	11	37.9
Late	18	62.1
Fetal prognosis
In live	87	75
Died	29	25

It appears from this table that 66.2% of pregnant women had received anti-syphilitic treatment. It emerges from this table that 50 pregnancies or 34.4% ended in a full-term delivery. It appears from this table that 18 abortions, or 62.1%, were late. 75% of pregnancies ended in a live fetus (see Table 3 on page 7).

Risk factors for syphilis in pregnancy

Sociodemographic characteristics

The table below presents the risk factors according to sociodemographic characteristics.

Table 4. Syphilis risk factors by sociodemographic characteristics.

Socio-démographic characteristics	Syphilis
Socio-démographic characteristics	Négative (n = 145)	Positive (n = 145)	OR	95% IC	p-value
Age
< 20 years	16 (48.5%)	17 (51.5%)	—	—
20 à 34 years	90 (50.3%)	89 (49.7%)	0.93	0.44 – 1.96	0.8
≥ 35 years	39 (50.0%)	39 (50.0%)	0.94	0.41 – 2.13	0.9
Marital status
Married	100 (52.9%)	89 (47.1%)	—	—
Single	45 (44.6%)	56 (55.4%)	1.4	0.86 – 2.28	0.2
Occupation
Private sector	17 (53.1%)	15 (46.9%)	—	—
State agent	25 (59.5%)	17 (40.5%)	0.77	0.30 – 1.95	0.6
Trader	21 (47.7%)	23 (52.3%)	1.24	0.50 – 3.12	0.6
Student	23 (44.2%)	29 (55.8%)	1.43	0.59 – 3.49	0.4
House keeper	28 (46.7%)	32 (53.3%)	1.3	0.55 – 3.09	0.6
Unemployed	31 (51.7%)	29 (48.3%)	1.06	0.45 – 2.52	0.9
Husband occupation
Teacher	17 (68.0%)	8 (32.0%)	—	—
State agent	30 (50.8%)	29 (49.2%)	2.05	0.79 – 5.72	0.2
Driver	10 (37.0%)	17 (63.0%)	3.61	1.18 – 11.9	0.028
Trader	10 (20.8%)	38 (79.2%)	8.08	2.81 – 25.4	<0.001
Student	7 (33.3%)	14 (66.7%)	4.25	1.28 – 15.5	0.022
Unemployed	26 (40.0%)	39 (60.0%)	3.19	1.23 – 8.83	0.02
Adress
Makiso	39 (61.9%)	24 (38.1%)	—	—
Kabondo	19 (100.0%)	0 (0.0%)	0		>0.9
Kisangani	11 (100.0%)	0 (0.0%)	0		>0.9
Lubunga	6 (100.0%)	0 (0.0%)	0		>0.9
Mangobo	37 (35.6%)	67 (64.4%)	2.94	1.55 – 5.69	0.001
Tshopo	33 (37.9%)	54 (62.1%)	2.66	1.37 – 5.24	0.004
Educational level
University	54 (60.7%)	35 (39.3%)	—	—
Elementary school	24 (35.8%)	43 (64.2%)	2.76	1.45 – 5.39	0.002
High school	67 (50.0%)	67 (50.0%)	1.54	0.90 – 2.67	0.12
Socio-economic level
High	39 (53.4%)	34 (46.6%)	—	—
Low	31 (41.3%)	44 (58.7%)	1.63	0.85 – 3.14	0.14
Middle	75 (52.8%)	67 (47.2%)	1.02	0.58 – 1.81	>0.9
Type of marriage
Monogamic	73 (53.7%)	63 (46.3%)	—	—
Polygamic	27 (52.9%)	24 (47.1%)	1.03	0.54 – 1.96	>0.9

Some of the husband’s occupation, certaines places of residence and the level of education are risk factors in our study. Women whose spouses were drivers, shopkeepers, students, and unemployed were more likely to contract syphilis than those whose spouses were teachers. Women who lived in Mangobo commune and those who resided in Tshopo commune were more likely to develop syphilis Women with primary education were 2.76 times more likely to develop syphilis than women with university education (see Table 4 on pages 7-8).

Antécédents

Women with a history of STIs were 2.97 times more likely to develop. Women who were on ARV treatment were 1.92 times more likely to develop syphilis. Pregnant women who had more than one sexual partner were 1.88 times more likely to develop syphilis (see Table 5 on page 9).

Table 5. Risk factors for syphilis in pregnancy by history.

Histories	Syphilis
Histories	Négative (N = 145)	Positive (N = 145)	OR	95% IC	P-valeur
Age (in in weeks of amenorrhea)
15-25	59 (50.0%)	59 (50.0%)	—	—
26-37	86 (50.0%)	86 (50.0%)	1	0.63 – 1.60	>0.9
Parity
Nulliparous	14 (50.0%)	14 (50.0%)	—	—
Primiparous	37 (50.0%)	37 (50.0%)	1	0.42 – 2.40	>0.9
Secondiparous	42 (50.0%)	42 (50.0%)	1	0.42 – 2.37	>0.9
Multiparous	52 (50.0%)	52 (50.0%)	1	0.43 – 2.32	>0.9
Gestité
Primigravida	5 (50.0%)	5 (50.0%)	—	—
Secondigesture	19 (50.0%)	19 (50.0%)	1	0.24 – 4.15	>0.9
Multigesture	121 (50.0%)	121 (50.0%)	1	0.27 – 3.68	>0.9
Type de grossesse
Monofetal	90 (50.0%)	90 (50.0%)	—	—
Twin	41 (50.0%)	41 (50.0%)	1	0.59 – 1.69	>0.9
Multiple	14 (50.0%)	14 (50.0%)	1	0.45 – 2.23	>0.9
Concept of STI
No	105 (60.7%)	68 (39.3%)	—	—
Yes	40 (34.2%)	77 (65.8%)	2.97	1.83 – 4.88	<0.001
Type of STI
Gonorrhea	16 (44.4%)	20 (55.6%)	1.95	—	0.1
Condyloma	7 (35.0%)	13 (65.0%)	1.29	0.37 – 4.61	0.7
Syphilis	12 (27.9%)	31 (72.1%)	1.79	0.60 – 5.31	0.3
Trichomonas	6 (31.6%)	13 (68.4%)	1.15	0.31 – 4.47	0.8
Anti-retroviral treatment
HIV-	123 (53.2%)	108 (46.8%)	—	—
HIV+ on ART	22 (37.3%)	37 (62.7%)	1.92	1.07 – 3.49	0.03
Notion of more than one sexual partner
No	103 (55.7%)	82 (44.3%)	—	—
Yes	42 (40.0%)	63 (60.0%)	1.88	1.16 – 3.08	0.011
Concept of male condom use
No	104 (50.0%)	104 (50.0%)	—	—
Yes	41 (50.0%)	41 (50.0%)	1	0.60 – 1.67	>0.9

Discussion

This case-control study conducted at Makiso Kisangani General Referral Hospital explored the association between syphilis during pregnancy and a range of socio-demographic, obstetric, and neonatal factors. Our findings provide valuable insights into the prevalence of syphilis among pregnant women in this setting, as well as its potential consequences for both the mother and the newborn. The methodology applied, including the matching of cases and controls, the use of reliable diagnostic tests (VDRL and TPHA), and the consideration of several clinical and social variables, strengthens the internal validity of the study. Nevertheless, certain limitations should be acknowledged when interpreting and generalizing the results, particularly the single-center design.

Risk factors for syphilis during pregnancy

According to Table 4, it emerges that:

• Pregnant women whose partners were drivers, merchants, students, and unemployed were at a higher risk of developing syphilis compared to those whose partners were teachers;
• Pregnant women residing in the communes of Mangobo and Tshopo were more likely to develop syphilis compared to those living in the Makiso commune;
• Pregnant women with a primary level of education were 2.76 times more likely to develop syphilis compared to those with secondary or university education.

Our findings are consistent with those of Katenga B. et al.,¹³ who found that having a partner who is a merchant was a risk factor for developing syphilis. Similarly, Meng Zhang et al.¹⁴ in China identified a primary level of education as a risk factor.

Considering the poverty in our community, merchants, drivers, and students are more likely to attract women and may have multiple sexual partners without using protective measures against STIs.

Pregnant women with a primary level of education lack sufficient knowledge about STIs, their prevention, and protection measures.

Table 5 indicates that having a history of STIs, receiving ARV treatment, and having multiple sexual partners were risk factors for developing syphilis among our pregnant women.

Our findings align with those of Jacob S et al.¹⁵ in Zambia, who confirmed that a history of STIs, multiple sexual partners, and HIV were significantly associated with maternal syphilis.

M. Tardieu et al.¹⁶ in France also found that a history of STIs and multiple sexual partners were the most frequently reported risk behaviors among pregnant women with syphilis.

Our findings could be explained by the fact that prevention and protection measures against STIs are not yet fully accepted and implemented in our communities due to certain religious and cultural beliefs that often oppose the use of some protective methods, such as condoms.

Maternal-fetal outcome in pregnant women with syphilis

Our results showed that 75% of pregnancies in pregnant women with syphilis resulted in the birth of a live fetus.

Our results are lower than those found by Moraes et al.¹⁷ in Brazil, where 86.5% of pregnancies had a favorable outcome and 13.5% had unfavorable outcomes. Similarly, Carles G. et al.¹⁸ in French Guiana reported a 20% fetal mortality rate.

This could be explained by the fact that, according to Fatima LUBUELA in the DRC,¹⁹ 80% of pregnant women start prenatal consultations late. Consequently, the detection and management of various pathologies occur late, increasing the risk of adverse pregnancy outcomes in case of complications.

Based on observations made during our study, our findings align with the conclusions drawn by this author.

Profile of pregnant women with syphilis

Age

We found that the most affected age group was between 20 and 34 years old (61.4%),

Our result is close to that found by Cyprin K. et al.²⁰ in Cameroon (68%).

This could be explained by the fact that, according to Roger T. et al.²¹ in the DRC, "84% of young girls have their first sexual intercourse at an average age of 15.98 years, and it is often unprotected." They are therefore not well informed about STI prevention and protection measures and have more time to develop such infections.

Marital status

The distribution of pregnant women by marital status shows a predominance of married women (61.4%) in our setting.

Cyprien K. et al.²⁰ in Cameroon and Nacer et al.²² in Morocco found that 80.3% and 96.9%, respectively, of married women or those living in cohabitation were affected by syphilis.

Our results can be explained by the fact that in our setting, the majority of pregnant women are married or living in cohabitation.

Occupation

Our study found that the majority of pregnant women with syphilis were housewives (22.1%).

Our results are similar to those found by Cyprien K. et al.²⁰ in Cameroon (49.4%) and those of Sangu K. et al.²³ in Benin, who made similar observations.

This could be explained by the fact that housewives are more numerous in the general population and are less informed about STIs and their prevention and protection measures, making them more vulnerable to contracting STIs.

Partner’s occupation

We observed that pregnant women whose partners were unemployed were the most affected (26.9%).

Kelah Z. et al.²⁴ in Tanzania observed a predominance of pregnant women whose partners were employed in the private sector.

This could be explained by the fact that 80% of the population in the DRC is unemployed, according to the summary of the book “Instruments of Economic Policy and the Fight Against Unemployment in the DRC.” As a result, they do not always have the financial means to acquire protection against STIs.

Educational level

In our study, we observed a high frequency of syphilis among pregnant women with a secondary level of education (46.2%).

Cyprien K. et al.²⁰ in Cameroon found that 43.0% of pregnant women with secondary education were affected by syphilis.

According to the secondary analysis of EDS-RDC, “educated women are more likely to engage in high-risk sexual behavior than uneducated women.”

However, based on our observations, our study does not align with this analysis, as pregnant women with a moderate level of education are more affected by syphilis in our setting.

Author contributions

• Conception and implementation: All authors
• Financial support: All authors
• Administrative support: All authors
• Provision of study material or patients: All authors
• Data collection and assembly: All authors
• Data analysis and interpretation: All authors
• Manuscript writing: All authors
• Final manuscript approval: All authors
• Responsible for all aspects of the work: All authors

Disclosure statement

The authors are employees of the University of Kisangani and the University of Mbujimayi.

Ethics and consent

This study received approval from the ethics committee of the University of Kisangani on UNIKIS/CER/024/2023 of 7th June 2023. It was conducted in accordance with the requirements of good clinical practices and the principles of the Helsinki Declaration of the World Medical Association, along with any subsequent relevant amendments. All women who have participated in this study have provided their consent by signing a written document.

Consent to publish

The participants also gave their consent for their data to be published. Our data collection was done anonymously. We have taken all measures not to publish any data that could facilitate the identification of participants.

Context key findings

• The prevalence of syphilis among pregnant women was 16.9%.
• This prevalence is higher than previous studies.
• This prevalence indicates the progression of this pathology in our setting.
• The risk factors were having a partner who is a driver, trader, student, or unemployed.
• Others risk factors were primary education level, history of STIs, ARV treatment, and multiple sexual partners.
• The maternal-fetal prognosis was favorable, with 75% of pregnancies resulting in live births.
• This shows the importance of diagnosing and treating syphilis in pregnant women.

Global health impact on policies and actions

• Targeted education and awareness for at-risk groups, such as drivers, shopkeepers, students, and people with multiple partners.
• Integrate syphilis testing into antenatal care to identify and treat infected pregnant women.
• Ensure the availability of penicillin, the treatment of choice for syphilis, in all health centres.
• Establish protocols to screen and treat newborns at risk of congenital syphilis.
• Improved data collection to better monitor prevalence and assess the effectiveness of interventions.

Data availability

Underlying data

Figshare: Syphilis in pregnancy: prevalence, risk factors and maternal-fetal prognosis in Kisangani. Doi: https://doi.org/10.6084/m9.figshare.28292933.v2.²⁵

This project contains the following underlying data:

• Base de données syphilis.xlsx

Data.xlsx [anonymised results of microscopic syphlis in pregnancy, Marital status (Married=1, Single =2),occupation (unemployed=1, State agent=2, Houde keeper=3, Private sector=4, trader=5, student=6), Adress (Makiso=1, Mangobo=2, Tshopo=3, Kabondo=4, Kisangani=5, Lubunga=6), Educational level (Elementary school=1, High school=2, university= 3), socio-economic level (low=1, Middle=2, high=3), Type of marriage (Monogamic=1, Polygamic=2), Type of pregnancy (Monofœtale=1,Gémellaire=2, Multiple=3), Route of past delivery (vaginnaly=1, cesarean=2), concept of STI (yes=1, No=2) ARV treatment (yes=1, No=2)].

Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).

Acknowledgement

We would like to thank Makiso General Referral Hospital Authorities for allowing us to carry out this study in their establishment.

References

1. Peeling RW, Hook EW: La pathogénèse de la syphilis: le Grand Mimicker, revisité. J. Pathol. 2006; 208: 224–232. PubMed Abstract | Publisher Full Text
2. Miller BA, Hicks CB: Syphilis and HIV: l’intersection de deux épidémies.2010. Consulté le 28 août 2023 à 19h30 minutes. Reference Source
3. Stamm LV: Global challenge of antibiotic resistant Treponema pallidum. Antimicrob. Agents Chemother. 2010feb; 54(2): 583–589. PubMed Abstract | Publisher Full Text | Free Full Text
4. World Health Organization: Prevalence and incidence of selected sexually transmitted infections chlamydia trachomatis, Neisseria gonorrhoeae, syphilis and trichomonas vaginalis: methods and results used by WHO to generate estimates for 2005. Geneva: World Health Organization; 2011.
5. Assurance maladie: Syphilis: définition, évolution et transmission. 2023. [Syphilis: definition, evolution and transmission]. Accessed on October 18, 2023 at 6:23 p.m. Reference Source
6. World health organization: 2023. Accessed on October 20, 2023 at 8:15 p.m. Reference Source
7. Joseph DDL, Shull HI, Billings JD, et al.: Prevalence of curable sexually transmitted infections among pregnant women in low- and middle-income countries, 2010–2015. une revue systématique. 2016; 43: 450–458. 10.1097OLQ.
8. WHO Guideline on syphilis screening and treatment for pregnat women.2017.
9. WHO: Global Sexually Transmitted Infections Surveillance Report 2018.
10. Emmanuel SK, Lado M, Amwayi S, et al.: Syphilis among pregnant women in juba, southern Sudan. East Afr. Med. J. 2010 May; 87(5): 192–198. PubMed Abstract | Publisher Full Text
11. Fatima N, Malik A, Khan PA: Seroprevalence of syphilis infection among patients attending antenatal care clinics: an observation from a tertiary care hospital in northern India. Am. J. Intern. Med. 2014; 2: 6. Publisher Full Text
12. Mani SB, Pegany R, Sheng D: Maternal syphilis: variation in prenatal screening, treatment, and diagnosis of congenital syphilis. Col. Med. Rev. 2017.
13. Katenga BG, Maindo AM: syphilis au cours de la grossesse dans la ville de Kisangani: prévalence, facteurs de risque et pronostic de la grossesse [syphilis during pregnancy in the city of Kisangani: prevalence, risk factors and prognosis of pregnancy]. KisMéd. Aout 2014; 5(1): 22–30.
14. Meng Z, Huimin Q, Feng X, et al.: factors associated with adverse pregnancy outcomes of maternal syphilis in Henan, China, 2016-2022. Epidemiol. Infect. 2023; 151: e170. PubMed Abstract | Publisher Full Text | Free Full Text
15. Jacob S, Nelllysiwe C, Selestine NA: Study on usefulness of a set of known risk factors in predicting maternal syphilis infections in three districts of western provience, Zambia. Pan Afr. Med. J. 2016; 24. eCollection. PubMed Abstract | Publisher Full Text | Free Full Text
16. Tardieu M, Mullaert J, Gerhardt P, et al.: Syphilis récidivante: facteurs de risque et caractéristiques cliniques et biologiques [Recurrent syphilis: risk factors and clinical and biological characteristics]. Annales de Dermatologie et de Vénérologie. Decembre 2014; 141(12, Supplement): S269–S270. Publisher Full Text
17. Barbosa de Moraes AR, Braz de Almeida AB, Labanca da Silva Azevêdo B, et al.: Epidemiological profile of gestational syphilis in a reference center in Northest Brazil: risk factors and trend from 2019 to 2021. DST j. bras. doenças sex. transm. jan.31,2023; 35. Publisher Full Text
18. Carles G, Lochet S, Youssef M, et al.: Syphilis and pregnancy, a study of 85 cases in French Guiana. Journal de Gynécologie Obstétrique et Biologie de la Reproduction. juin 2008; 37(4): 353–357. PubMed Abstract | Publisher Full Text
19. Fatima L: Mémoire: étude sur les causes du début de la CPN. Cas du centre mère et enfant de Bumbu [study on the causes of the onset of ANC. Case of the mother and child center of Bumbu]. Kinshasa (DRC): Université Pédagogique Nationale; 2015.
20. Cyprien K, Jean de Dieu A, Gabriel L, et al.: Highlighting a population-based re-emergence of syphilis infection and assessing associated risk factors among pregnant women in cameroon: evidence from the 2009 and 2017 national sentinel surveillance surveys of HIV and syphils. PLoS One. 2020; 15(11): e0241999. PubMed Abstract | Publisher Full Text | Free Full Text
21. Roger T, Maurice S, Hermann T, et al.: Sexualité des jeunes en milieu scolaire dans la ville de Likasi en République Démocratique du Congo [Sexuality of young people in schools in the city of Likasi in the Democratic Republic of Congo]. Pan Afr. Med. J. 2018; 31: 34. PubMed Abstract | Publisher Full Text | Free Full Text
22. Nacer N, Rkha S, Fatimi: Prévalence de la syphilis et de l’infection à VIH chez les femmes en âge de reproduction dans un contexte de vulnérabilité sociale au Maroc. [Prevalence of syphilis and HIV infection among women of reproductive age in a context of social vulnerability in Morocco]. Rev. Epidemiol. Sante Publique. 2023; 71: 101712. Publisher Full Text
23. Sangu: Facteurs de risque de la syphilis chez les femmes en période d’activité génitale et gestantes de 4 communes de Porto-Novo au bénin [Risk factors for syphilis in women with genital activity and pregnantism in 4 communes of Porto-Novo in Benin]. PAMJ. 2021; 3(20): 47–52.
24. Kelah Z: les infections sexuellement transmissibles les plus fréquentes chez les femmes enceintes d’Arusha en Tanzanie [the most common sexually transmitted infections among pregnant women in Arusha, Tanzania]. Tunisie médicale. 2020; 4(3): 48–50.
25. Lufuluabu MA, Likilo OJ, Tshodi, et al.: Syphilis in pregnancy: prevalence, risk factors and maternal-fetal prognosis in Kisangani. Dataset. figshare. 2025. Publisher Full Text

Comments on this article Comments (0)

Version 2

VERSION 2 PUBLISHED 25 Feb 2025

Author details Author details

¹ gynécology et obstétric, University of Kisangani, Kisangani, TSHOPO, Democratic Republic of the Congo
² Gynecology and obstetric, University of MBUJIMAYI, MBUJIMAYI, Eastern Kasai, Democratic Republic of the Congo
³ Internal medecine, University of Mbujimayi, MBUJIMAYI, Eastern Kasai, Democratic Republic of the Congo

Likilo Osundja Jérémie
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Tshodi Bulanda Arsène
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Lufuluabu Mpemba Alphonse
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Mbohou Kouaming Aminate Nawal
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Komanda Likeweke Emmanuel
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Katenga Bosunga Gédéon
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Competing interests

No competing interests were disclosed.

Grant information

The author(s) declared that no grants were involved in supporting this work.

Article Versions (2)

version 2

Revised

Published: 19 Sep 2025, 14:232

https://doi.org/10.12688/f1000research.161666.2

version 1

Published: 25 Feb 2025, 14:232

https://doi.org/10.12688/f1000research.161666.1

Copyright

© 2025 Jérémie LO et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download

Export To

metrics

	Views	Downloads
F1000Research	-	-
PubMed Central Data from PMC are received and updated monthly.	-	-

Citations

0

SEE MORE DETAILS

CITE

how to cite this article

Jérémie LO, Arsène TB, Alphonse LM et al. Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in Kisangani [version 2; peer review: 2 not approved]. F1000Research 2025, 14:232 (https://doi.org/10.12688/f1000research.161666.2)

NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.

track

receive updates on this article

Track an article to receive email alerts on any updates to this article.

Open Peer Review

Version 1

VERSION 1

PUBLISHED 25 Feb 2025

Views

11

Reviewer Report 16 Apr 2025

Michael Marks, London School of Hygiene and Tropical Medicine, London, UK

Not Approved

https://doi.org/10.5256/f1000research.177732.r375522

Introduction.
In general this needs restructuring - the first 5-6 paragraphs jumps back and forth between burden estimates, impact of disease etc. Please try and make this clearer. In particular you need to make clearer that syphilis at any ... Continue reading

Introduction.
In general this needs restructuring - the first 5-6 paragraphs jumps back and forth between burden estimates, impact of disease etc. Please try and make this clearer. In particular you need to make clearer that syphilis at any stage of pregnancy is associated with adverse outcomes. This could all be restructured into 1-2 paragraphs.

Please note some sentences are still written in French mixed in with English and need translating.

Please try and use more person centered language - i.e. pregnant women with syphilis rather than syphilis-positive or syphilis-negative.

The methods jumps straight into the number of individuals with/without syphilis - but there is no description of how people were identified, screened and their disease status classified. Was this all pregnant women? What tests were performed etc - were they study specific tests or routine tests etc. This is then touched on in the inclusion/exclusion but is hard to follow. The numbers of eventual participants should also be in results not methods.

There is no CONSORT diagram for study inclusion/exclusion which should be inclued.

I. would be worried that your inclusion and exlcusion criteria introduce significant bias. You have only included people who attended at least 4 ANC visits. This is likely to mean you have under-represented populations most at risk of syphilis and of adverse outcomes.

Some of the variables need to be explained such as 'type of marriage' , obstetric formula. Please review and make sure all variables are clear.

This statement "
The prevalence of syphilis in this study is calculated taking into account the total number of women who tested positive for syphilis, 165, compared to the total number of women tested, 976." doesn't make any sense. Was a sample size calculation actually performed?

Throughout only point estimates are provided without confidence intervals. This needs to be looked at through all the results.

Table 1&3 could likely be combined into a single table. I am not sure table 2 adds anything to the information in the text.

I dont understand what is meant by concept of STI in table 4.

Table 5 - how was treatment defined? Did this mean a single dose of BPG or 3 doses?

Some of the participants appear to be young - are there any participants <18 & if so how was consent obtained from this group?

In general there are too many table and a lot of repetition. I would suggest a single table for demographics and baseline features, one for syphilis status overall and by baseline characteristics, one on pregnancy outcome would be much easier to follow.

The discussion really needs a complete overhaul as its currently written almost in bullet point fashion. Please revisit this once you have revised other parts of the manuscript.

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Partly
Are sufficient details of methods and analysis provided to allow replication by others?

Partly
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Epidemiology, Syphilis, Sexually Transmitted Infections, Clinical Trials

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

CITE

Report a concern

Respond or Comment

Views

13

Reviewer Report 07 Apr 2025

Tendesayi Kufa, National Institute for Communicable Diseases, Johannesburg, South Africa

Not Approved

https://doi.org/10.5256/f1000research.177732.r372411

Thank you for the opportunity to review this paper. It addresses the important topic of maternal syphilis, the demographic and clinical risk factors as well as outcomes. The paper presents finding from a hospital based case –control study meant to ... Continue reading

Thank you for the opportunity to review this paper. It addresses the important topic of maternal syphilis, the demographic and clinical risk factors as well as outcomes. The paper presents finding from a hospital based case –control study meant to study risk factors. The paper was not very well presented and have highlighted areas for improvement.

1.   Abstract
•   Objectives: the author state that the objective of the study was to present current data and improve management of syphilis. They don’t state what data is being referred to.
•   Methods: the abstract methods don’t state where in the hospital the women were enrolled from. Also what was the inclusion/ exclusion criteria was?
•   Results: in the abstract results the authors state the prevalence of syphilis was 16.9%. In which population was this. Ordinarily if it’s a case control study, it makes no sense to present the prevalence as the cases and controls are selected. In the manuscript text, the authors report that it was among women screened for eligibility to enroll. This should be stated explicitly in the abstract. Also include other non-live birth outcomes in the abstract

Manuscript text
Introduction
•   Paragraph 1 - First let the reader know what syphilis is before discussing the cause
•   Paragraph 2 – the first sentence in the paragraph is in French. I am unable to read French
•   General objective – again the authors list the general objective as that to present current data without stating which data they are talking about. The objectives have to be specific
o   e.g. describe maternal syphilis seropositivity among women attending ANC at Makiso Kisangani General Referral Hospital (HGR) during the period from July 1, 2023, to December 1, 2023.
o   To identify the demographic and clinical risk factors for syphilis among study participants
o   To determine the maternal and fetal prognosis of syphilis during pregnancy.
The study itself cannot improve the management of syphilis but its findings can inform the management

Methods
•   Study population- can the authors describe the setting of the study a little better. Where is this hospital, which pregnant women are referred to this hospital’s obstetric services? What is the attendance at this clinic per month etc.?
•   Were all the 976 women attending the clinic or there was some selection to get to the 976 women?
•   Is the inclusion / exclusion criteria for the initial syphilis screening (that gave rise to the 976 women) or it was specifically for cases
•   Under type of study – remove analytical in describing the design as case-control. Case-control studies are by definition analytical
•   In the section on statistical analysis the authors refer to results being presented in tables. What results are being referred to here? The statistical methods should be described in such a way that the analysis is reproducible by others
•   Data on the syphilis prevalence belongs to the results section
•   Ethical considerations need to be better described. What were the women consenting to? How was their data kept confidential?

Results
•   Table 1: please also include the socio-demographic characteristics of controls as well
•   Table 2 is confusing. Were the 976 part of the study or not. If the study is a case-control study including 145 cases and 145 controls, then the prevalence of syphilis shouldn’t be reported as its artificial. The authors should report syphilis positivity among those screened for eligibility to take part in the case control study
•   In table 3 – also include data on the controls
•   What is meant by deaths in Table 3. Are these previous fetal deaths?
•   Also include data on the controls in table 4
•   In table 4 can the authors also include other maternal comorbidities that can predispose women to poor obstetric outcomes. These maybe gestational hypertension, diabetes, heart disease, TB etc.
•   There are too many tables. Tables 1, 2 and 4 can be combined in one table
•   Table 6 – what is meant by MIU. Include data on controls in table 6
•   Can the authors please present pregnancy outcomes of controls as well. Was
•   In table 8 – the ART variable could be coded as HIV-, HIV+ on ART and HIV + not on ART
•   Some results are written in French. Made it difficult to follow

Discussion
•   The authors wrote that their study proved the rate of syphilis among pregnant women went up. The study doesn't proof this. Without prior data the authors cannot say this. Without describing how the women got to be selected when they attended the hospital you can say this either
•   Please clarify who the study participants were. In the methods women were screened and then enrolled. Only those enrolled are considered participants
•   The study found that having a partner who was a driver, trader, student or unemployed was associated with higher odds of having syphilis. What is the intervention or public health action associated with this finding? The same goes for all the factors identified in the analysis
•   This discussion is written in lines and not proper paragraphs. Can the authors address this?
•   The study does not discuss any strengths or limitations. Please add these

Data availability
The dataset is in French. Can the authors provide one in English too?

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

No
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

No
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Epidemiology, infectious diseases, syphilis, STIs

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

CITE

Report a concern

Respond or Comment

Comments on this article Comments (0)

Version 2

VERSION 2 PUBLISHED 25 Feb 2025

Open Peer Review

Reviewer Status

Reviewer Reports

	Invited Reviewers
	1	2
Version 2 (revision) 19 Sep 25
Version 1 25 Feb 25	read	read

Tendesayi Kufa, National Institute for Communicable Diseases, Johannesburg, South Africa
Michael Marks, London School of Hygiene and Tropical Medicine, London, UK

Comments on this article

All Comments(0)

Add a comment

Sign up for content alerts

Browse by related subjects

Back to all reports

Reviewer Report

11 Views

16 Apr 2025 | for Version 1

Michael Marks, London School of Hygiene and Tropical Medicine, London, UK

11 Views Cite this report Responses(0)

Not Approved

Introduction.
In general this needs restructuring - the first 5-6 paragraphs jumps back and forth between burden estimates, impact of disease etc. Please try and make this clearer. In particular you need to make clearer that syphilis at any stage of pregnancy is associated with adverse outcomes. This could all be restructured into 1-2 paragraphs.

Please note some sentences are still written in French mixed in with English and need translating.

Please try and use more person centered language - i.e. pregnant women with syphilis rather than syphilis-positive or syphilis-negative.

The methods jumps straight into the number of individuals with/without syphilis - but there is no description of how people were identified, screened and their disease status classified. Was this all pregnant women? What tests were performed etc - were they study specific tests or routine tests etc. This is then touched on in the inclusion/exclusion but is hard to follow. The numbers of eventual participants should also be in results not methods.

There is no CONSORT diagram for study inclusion/exclusion which should be inclued.

I. would be worried that your inclusion and exlcusion criteria introduce significant bias. You have only included people who attended at least 4 ANC visits. This is likely to mean you have under-represented populations most at risk of syphilis and of adverse outcomes.

Some of the variables need to be explained such as 'type of marriage' , obstetric formula. Please review and make sure all variables are clear.

This statement "
The prevalence of syphilis in this study is calculated taking into account the total number of women who tested positive for syphilis, 165, compared to the total number of women tested, 976." doesn't make any sense. Was a sample size calculation actually performed?

Throughout only point estimates are provided without confidence intervals. This needs to be looked at through all the results.

Table 1&3 could likely be combined into a single table. I am not sure table 2 adds anything to the information in the text.

I dont understand what is meant by concept of STI in table 4.

Table 5 - how was treatment defined? Did this mean a single dose of BPG or 3 doses?

Some of the participants appear to be young - are there any participants <18 & if so how was consent obtained from this group?

In general there are too many table and a lot of repetition. I would suggest a single table for demographics and baseline features, one for syphilis status overall and by baseline characteristics, one on pregnancy outcome would be much easier to follow.

The discussion really needs a complete overhaul as its currently written almost in bullet point fashion. Please revisit this once you have revised other parts of the manuscript.

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Partly
Are sufficient details of methods and analysis provided to allow replication by others?

Partly
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Epidemiology, Syphilis, Sexually Transmitted Infections, Clinical Trials

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

Respond to this report

Responses (0)

Back to all reports

Reviewer Report

13 Views

07 Apr 2025 | for Version 1

Tendesayi Kufa, National Institute for Communicable Diseases, Johannesburg, South Africa

13 Views Cite this report Responses(0)

Not Approved

Thank you for the opportunity to review this paper. It addresses the important topic of maternal syphilis, the demographic and clinical risk factors as well as outcomes. The paper presents finding from a hospital based case –control study meant to study risk factors. The paper was not very well presented and have highlighted areas for improvement.

1.   Abstract
•   Objectives: the author state that the objective of the study was to present current data and improve management of syphilis. They don’t state what data is being referred to.
•   Methods: the abstract methods don’t state where in the hospital the women were enrolled from. Also what was the inclusion/ exclusion criteria was?
•   Results: in the abstract results the authors state the prevalence of syphilis was 16.9%. In which population was this. Ordinarily if it’s a case control study, it makes no sense to present the prevalence as the cases and controls are selected. In the manuscript text, the authors report that it was among women screened for eligibility to enroll. This should be stated explicitly in the abstract. Also include other non-live birth outcomes in the abstract

Manuscript text
Introduction
•   Paragraph 1 - First let the reader know what syphilis is before discussing the cause
•   Paragraph 2 – the first sentence in the paragraph is in French. I am unable to read French
•   General objective – again the authors list the general objective as that to present current data without stating which data they are talking about. The objectives have to be specific
o   e.g. describe maternal syphilis seropositivity among women attending ANC at Makiso Kisangani General Referral Hospital (HGR) during the period from July 1, 2023, to December 1, 2023.
o   To identify the demographic and clinical risk factors for syphilis among study participants
o   To determine the maternal and fetal prognosis of syphilis during pregnancy.
The study itself cannot improve the management of syphilis but its findings can inform the management

Methods
•   Study population- can the authors describe the setting of the study a little better. Where is this hospital, which pregnant women are referred to this hospital’s obstetric services? What is the attendance at this clinic per month etc.?
•   Were all the 976 women attending the clinic or there was some selection to get to the 976 women?
•   Is the inclusion / exclusion criteria for the initial syphilis screening (that gave rise to the 976 women) or it was specifically for cases
•   Under type of study – remove analytical in describing the design as case-control. Case-control studies are by definition analytical
•   In the section on statistical analysis the authors refer to results being presented in tables. What results are being referred to here? The statistical methods should be described in such a way that the analysis is reproducible by others
•   Data on the syphilis prevalence belongs to the results section
•   Ethical considerations need to be better described. What were the women consenting to? How was their data kept confidential?

Results
•   Table 1: please also include the socio-demographic characteristics of controls as well
•   Table 2 is confusing. Were the 976 part of the study or not. If the study is a case-control study including 145 cases and 145 controls, then the prevalence of syphilis shouldn’t be reported as its artificial. The authors should report syphilis positivity among those screened for eligibility to take part in the case control study
•   In table 3 – also include data on the controls
•   What is meant by deaths in Table 3. Are these previous fetal deaths?
•   Also include data on the controls in table 4
•   In table 4 can the authors also include other maternal comorbidities that can predispose women to poor obstetric outcomes. These maybe gestational hypertension, diabetes, heart disease, TB etc.
•   There are too many tables. Tables 1, 2 and 4 can be combined in one table
•   Table 6 – what is meant by MIU. Include data on controls in table 6
•   Can the authors please present pregnancy outcomes of controls as well. Was
•   In table 8 – the ART variable could be coded as HIV-, HIV+ on ART and HIV + not on ART
•   Some results are written in French. Made it difficult to follow

Discussion
•   The authors wrote that their study proved the rate of syphilis among pregnant women went up. The study doesn't proof this. Without prior data the authors cannot say this. Without describing how the women got to be selected when they attended the hospital you can say this either
•   Please clarify who the study participants were. In the methods women were screened and then enrolled. Only those enrolled are considered participants
•   The study found that having a partner who was a driver, trader, student or unemployed was associated with higher odds of having syphilis. What is the intervention or public health action associated with this finding? The same goes for all the factors identified in the analysis
•   This discussion is written in lines and not proper paragraphs. Can the authors address this?
•   The study does not discuss any strengths or limitations. Please add these

Data availability
The dataset is in French. Can the authors provide one in English too?

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

No
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

No
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Epidemiology, infectious diseases, syphilis, STIs

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

Respond to this report

Responses (0)

[1] 1. Peeling RW, Hook EW: La pathogénèse de la syphilis: le Grand Mimicker, revisité. J. Pathol. 2006; 208: 224–232. PubMed Abstract | Publisher Full Text

[2] 2. Miller BA, Hicks CB: Syphilis and HIV: l’intersection de deux épidémies.2010. Consulté le 28 août 2023 à 19h30 minutes. Reference Source

[3] 3. Stamm LV: Global challenge of antibiotic resistant Treponema pallidum. Antimicrob. Agents Chemother. 2010feb; 54(2): 583–589. PubMed Abstract | Publisher Full Text | Free Full Text

[4] 4. World Health Organization: Prevalence and incidence of selected sexually transmitted infections chlamydia trachomatis, Neisseria gonorrhoeae, syphilis and trichomonas vaginalis: methods and results used by WHO to generate estimates for 2005. Geneva: World Health Organization; 2011.

[5] 5. Assurance maladie: Syphilis: définition, évolution et transmission. 2023. [Syphilis: definition, evolution and transmission]. Accessed on October 18, 2023 at 6:23 p.m. Reference Source

[6] 6. World health organization: 2023. Accessed on October 20, 2023 at 8:15 p.m. Reference Source

[7] 7. Joseph DDL, Shull HI, Billings JD, et al.: Prevalence of curable sexually transmitted infections among pregnant women in low- and middle-income countries, 2010–2015. une revue systématique. 2016; 43: 450–458. 10.1097OLQ.

[8] 8. WHO Guideline on syphilis screening and treatment for pregnat women.2017.

[9] 9. WHO: Global Sexually Transmitted Infections Surveillance Report 2018.

[10] 10. Emmanuel SK, Lado M, Amwayi S, et al.: Syphilis among pregnant women in juba, southern Sudan. East Afr. Med. J. 2010 May; 87(5): 192–198. PubMed Abstract | Publisher Full Text

[11] 11. Fatima N, Malik A, Khan PA: Seroprevalence of syphilis infection among patients attending antenatal care clinics: an observation from a tertiary care hospital in northern India. Am. J. Intern. Med. 2014; 2: 6. Publisher Full Text

[12] 12. Mani SB, Pegany R, Sheng D: Maternal syphilis: variation in prenatal screening, treatment, and diagnosis of congenital syphilis. Col. Med. Rev. 2017.

[13] 13. Katenga BG, Maindo AM: syphilis au cours de la grossesse dans la ville de Kisangani: prévalence, facteurs de risque et pronostic de la grossesse [syphilis during pregnancy in the city of Kisangani: prevalence, risk factors and prognosis of pregnancy]. KisMéd. Aout 2014; 5(1): 22–30.

[14] 14. Meng Z, Huimin Q, Feng X, et al.: factors associated with adverse pregnancy outcomes of maternal syphilis in Henan, China, 2016-2022. Epidemiol. Infect. 2023; 151: e170. PubMed Abstract | Publisher Full Text | Free Full Text

[15] 15. Jacob S, Nelllysiwe C, Selestine NA: Study on usefulness of a set of known risk factors in predicting maternal syphilis infections in three districts of western provience, Zambia. Pan Afr. Med. J. 2016; 24. eCollection. PubMed Abstract | Publisher Full Text | Free Full Text

[16] 16. Tardieu M, Mullaert J, Gerhardt P, et al.: Syphilis récidivante: facteurs de risque et caractéristiques cliniques et biologiques [Recurrent syphilis: risk factors and clinical and biological characteristics]. Annales de Dermatologie et de Vénérologie. Decembre 2014; 141(12, Supplement): S269–S270. Publisher Full Text

[17] 17. Barbosa de Moraes AR, Braz de Almeida AB, Labanca da Silva Azevêdo B, et al.: Epidemiological profile of gestational syphilis in a reference center in Northest Brazil: risk factors and trend from 2019 to 2021. DST j. bras. doenças sex. transm. jan.31,2023; 35. Publisher Full Text

[18] 18. Carles G, Lochet S, Youssef M, et al.: Syphilis and pregnancy, a study of 85 cases in French Guiana. Journal de Gynécologie Obstétrique et Biologie de la Reproduction. juin 2008; 37(4): 353–357. PubMed Abstract | Publisher Full Text

[19] 19. Fatima L: Mémoire: étude sur les causes du début de la CPN. Cas du centre mère et enfant de Bumbu [study on the causes of the onset of ANC. Case of the mother and child center of Bumbu]. Kinshasa (DRC): Université Pédagogique Nationale; 2015.

[20] 20. Cyprien K, Jean de Dieu A, Gabriel L, et al.: Highlighting a population-based re-emergence of syphilis infection and assessing associated risk factors among pregnant women in cameroon: evidence from the 2009 and 2017 national sentinel surveillance surveys of HIV and syphils. PLoS One. 2020; 15(11): e0241999. PubMed Abstract | Publisher Full Text | Free Full Text

[21] 21. Roger T, Maurice S, Hermann T, et al.: Sexualité des jeunes en milieu scolaire dans la ville de Likasi en République Démocratique du Congo [Sexuality of young people in schools in the city of Likasi in the Democratic Republic of Congo]. Pan Afr. Med. J. 2018; 31: 34. PubMed Abstract | Publisher Full Text | Free Full Text

[22] 22. Nacer N, Rkha S, Fatimi: Prévalence de la syphilis et de l’infection à VIH chez les femmes en âge de reproduction dans un contexte de vulnérabilité sociale au Maroc. [Prevalence of syphilis and HIV infection among women of reproductive age in a context of social vulnerability in Morocco]. Rev. Epidemiol. Sante Publique. 2023; 71: 101712. Publisher Full Text

[23] 23. Sangu: Facteurs de risque de la syphilis chez les femmes en période d’activité génitale et gestantes de 4 communes de Porto-Novo au bénin [Risk factors for syphilis in women with genital activity and pregnantism in 4 communes of Porto-Novo in Benin]. PAMJ. 2021; 3(20): 47–52.

[24] 24. Kelah Z: les infections sexuellement transmissibles les plus fréquentes chez les femmes enceintes d’Arusha en Tanzanie [the most common sexually transmitted infections among pregnant women in Arusha, Tanzania]. Tunisie médicale. 2020; 4(3): 48–50.

[25] 25. Lufuluabu MA, Likilo OJ, Tshodi, et al.: Syphilis in pregnancy: prevalence, risk factors and maternal-fetal prognosis in Kisangani. Dataset. figshare. 2025. Publisher Full Text

Syphilis in pregnancy: Risk factors and maternal-fetal prognosis in Kisangani

Abstract

Background

Objective

Methods

Results

Conclusion

Keywords

Revised Amendments from Version 1

Introduction

General objective

Specific objectives

Methods

Study population

Inclusion criteria

Exclusion criteria

Type of study

Data collection technique

Figure 1. Flowchart of study population selection for case-control study on syphilis among pregnant women in Kisangani.

Operational definitions

Statistical analysis

Ethical considerations

Consent to publish

Results

Sociodemographic characteristics and gynecological antecedent of pregnant women with syphilis

Table 1. Distribution of syphilis cases by sociodemographic characteristics and gynecological antecedent.

Table 2. Distribution of cases by obstetrical history.

Table 3. Presentation of cases by syphilis treatment received, pregnancy outcome, type of abortion, fetal prognosis.

Risk factors for syphilis in pregnancy

Table 4. Syphilis risk factors by sociodemographic characteristics.

Table 5. Risk factors for syphilis in pregnancy by history.

Discussion

Risk factors for syphilis during pregnancy

Maternal-fetal outcome in pregnant women with syphilis

Profile of pregnant women with syphilis

Author contributions

Disclosure statement

Ethics and consent

Consent to publish

Context key findings

Global health impact on policies and actions

Data availability

Underlying data

Acknowledgement

References

Comments on this article Comments (0)

Open Peer Review

Comments on this article Comments (0)

Open Peer Review

Reviewer Status

Reviewer Reports

Comments on this article

Browse by related subjects

Competing Interests Policy

Stay Updated