Comparative evaluation of gestosis score vs uterine artery pulsatility index in predicting gestational hypertension: A study protocol

Background

As outlined by the American College of Obstetrics and Gynaecology (ACOG), gestational hypertension is defined as systolic blood pressure of 140mmHg or more or diastolic blood pressure of 90mmHg or more on two instances of at least four hours apart after 20 weeks of gestation of pregnancy in previously normotensive women.¹ When this high blood pressure is associated with proteinuria, it is known as preeclampsia.

Gestational hypertension is a major medical problem during pregnancy, with possible adverse implications on both mother's and fetal health.^2–4 It is critical to predict and identify high-risk pregnancies early to provide proper monitoring and care. The pooled prevalence of Hypertensive disorders of pregnancy (HDOP) in India is 9% (95% CI, 8%–10%), which is significantly higher than the global prevalence, as reported in a study done in pregnant women of the Indian population.⁵

Many initiatives have been carried out to anticipate and avert the onset of gestational hypertension and other pregnancy-related hypertensive disorders of pregnancy because of their epidemiological and clinical significance. In clinical settings, a variety of predictive multiparametric algorithms are employed. These algorithms utilize multiple maternal risk factors, radiological evaluations such as the uterine artery Doppler pulsatility index, and diverse plasma biomarkers to achieve their intended purpose.^6–13 Despite the rising efficacy of these approaches, the actual predictive models for gestational hypertension are still a source of contention and hence not yet used in routine clinical practice.

Hence there is a need to analyze and promote newer predictive models which can help in predicting the occurrence of hypertensive disorders during pregnancy.

The purpose of this clinical study is to examine the effectiveness of two prediction approaches, the Gestosis Score and the Uterine Artery Pulsatility Index, in predicting the risk of developing gestational hypertension in pregnant women in the second trimester between the gestational age of 13 weeks to 20 weeks.

Gestosis score is a newly developed scoring system consisting of known and newly emerging risk factors for gestational hypertension developed by Dr. Gorakh Mandrupkar and modified by the FOGSI-ICOG committee (Table 1).¹⁴ The gestosis score is proposed to ensure accurate screening and prediction of gestational hypertension and hypertensive disorders of pregnancy.

This scoring system takes into account both established and newly recognized factors that are linked to the causation of gestational hypertension. The score of 1, 2, or 3 for each clinical risk factor is determined based on its impact on the development of gestational hypertension. After conducting a thorough assessment and gathering detailed medical histories of the women, a cumulative score is determined for each participant. Women with a total score of 1 will be labeled low risk, a score of 2 will be labeled moderate risk and women with a total score of 3 or more will be labelled at high risk for development of gestational hypertension. As per one Indian study a gestosis score of 3 or more, appears to have promising diagnostic accuracy (95.35%) for predicting the development of preeclampsia (PE). It demonstrates good sensitivity (83.1%) and specificity (97.51%). The study showed the PPV of gestosis score in predicting preeclampsia is 85.51%, representing the likelihood of a positive result, while the NPV is 97.03%, indicating the probability of a negative result. This suggests it may be a useful early marker for identifying the risk of gestational hypertension and preeclampsia.¹⁵

Uterine artery Doppler velocimetry will be performed in the same women using a transabdominal probe. The pulsatility index will be measured in both uterine arteries and the mean will be calculated. Reference values for uterine artery pulsatility index are different for different gestational ages. Women with a mean pulsatility index more than the 95^th percentile of the reference range for the given gestational age will be labeled as high risk and other women with a pulsatility index within the normal level that is below the 95^th percentile will be labeled as mild risk for development of gestational hypertension.¹⁶

All these women will be routinely monitored during each ANC visit, blood pressure will be monitored regularly to detect de novo development of hypertension during their pregnancy.

Protocol

Registration: The trial has been registered with CTRI (REF/2023/04/065978).

Outcomes

At the end of this study, we will know whether the gestosis score has better predictive values as compared to the uterine artery pulsatility index in predicting gestational hypertension.

Discussion

As gestational hypertension has morbid consequences on the outcome of pregnancy, there is a need not only for diagnosis and management of gestational hypertension but also for methods that will help in identifying women who may develop gestational hypertension in pregnancy. This study evaluates the predictive abilities of two such methods, gestosis score with uterine artery pulsatility index with the expected outcome of gestosis score being better radiological evaluation in detecting at-risk pregnant women. This study will help in employing gestosis score as a screening method at health centers where ultrasonography or other expensive biochemical investigations cannot be done.

High-risk pregnancies will be diagnosed earlier and managed accordingly to provide healthy outcomes and safe motherhood to women.