Case Report: Neglected shoulder presentation in a full-term pregnancy: A rare obstetric emergency with heavy morbidity

Introduction

Shoulder presentation in term pregnancies is a rare form of transverse lie. It represents an exceptional obstetric situation, occurring in less than 1% of full-term gestations.¹

Due to the high risk of maternal and fetal complications, this situation is a real emergency, especially in case of delayed diagnosis or inadequate management.²

This fetal presentation exhibits a major risk of dystocia, uterine rupture, hemorrhage and high fetal and maternal mortality, particularly in the absence of quick and appropriate management.³

Herein, we report a case of a neglected shoulder presentation in a full-term pregnancy, highlighting the diagnostic and therapeutic challenges linked to this complication.

Case presentation

This is the case of a 32-year-old patient, Para 2, without any particular medical, surgical or obstetric history, residing in a rural zone, having one vaginal delivery of a healthy baby in a vertex presentation without maternal or neonatal complication.

The current pregnancy wasn’t well monitored, with only two prenatal consultations.

The available prenatal explorations did not reveal any evidence of abnormality or high-risk features. A morphology ultrasound performed at 22 weeks of gestation, showed a female fetus in a variable position without any visible abnormalities. No other ultrasonography was performed.

At 39 weeks of gestation, the patient consulted a level 1 peripheral maternity care center for pelvic pain related to the onset of labor.

The initial obstetric examination suggested a transverse lie.

Abdominal palpation revealed that the cephalic pole was in the right flank while the breech was in the left one. The vaginal examination discovered an empty pelvic cavity with no perceptible head or breech, which pointed to the presence of the shoulder at the level of the pelvic inlet.

Due to the lack of adequate technical platforms in this maternity unit, the patient was transferred to a level III maternity center for better management.

Upon arrival, the patient had a normal body temperature with a blood pressure of 110/65 mmHg, heart rate at 82 bpm and good general condition.

The physical examination showed that the right fetal hand (cyanosed) prolapsed and visible through the vaginal opening. The delay between the prolapse of the hand and hospital admission was about an hour.

The cervical dilation was 7 cm, and a neglected shoulder presentation was noted. ( Figure 1)

Figure 1. Neglected shoulder presentation in a full-term pregnancy.

The right fetal hand was cyanosed and prolapsed through the vaginal opening.

An emergency ultrasound was performed, confirming the transverse lie with a positive fetal heartbeat.

The patient was, immediately, conveyed to the operating room. A cesarean section was performed under spinal anesthesia. The fetal extraction was made possible owing to an internal version maneuver followed by a podalic extraction. It was a female newborn weighing 3300 g, with an immediate Apgar score of 8 and 9 at the fifth minute. The prolapsed hand was carefully and smoothly freed without trauma or damage during the extraction maneuver. Although this extraction was difficult, it had no impact on the hysterotomy, which remained intact without tearing or rupture.

The post operation evolution was uneventful for both the mother and the baby. The examination of the newborn didn’t reveal any traumatic lesion such as dislocation or fracture of the shoulder or paralysis of the brachial plexus. The newborn was admitted to the neonatology unit for a 24-hour surveillance and was then discharged without sequelae.

Discussion

Transverse lies are considered rare abnormalities of fetal presentation. They account for 0.5 to 1% of term pregnancies.³

It is defined by the fetus lying along a transverse axis, perpendicular to that of the uterus, which makes vaginal delivery impossible if this position persists during labor.¹

Typically, the neglected shoulder presentation represents a cluster of complications resulting from a persistent, untreated transverse lie, during several hours of active labor.⁴

This is a situation where, in the absence of diagnosis of a transverse presentation, the fetal shoulder becomes impacted in the maternal pelvis, hindering any progression of labor.⁵

This is exactly what we observed in our patient who was admitted with an advanced cervical dilation (7 cm) and a right prolapsed fetal hand which represents a late sign but suggests a severe mechanical impasse. The cyanosis observed in the fetal hand highlights the immediate risk of fetal hypoxia. This Lack of oxygen could possibly be linked to a compression of the umbilical cord or to fetal distress secondary to the prolonged shoulder entrapment.

This pathological situation is often due to the lack of surveillance or incomplete obstetrical examination, particularly in a resource-limited facility.⁴

Classically, Risk factors associated with transverse lie include: multiparity, polyhydramnios, prematurity, uterine malformation or affections (bicornuate or scarred uterus), fetal malformations and placentation abnormalities such as, placenta previa.⁶

These situations promote excessive fetal mobility and instability of fetal presentation at the end of pregnancy.⁴

None of these factors were found in this case. However, the rural context, the poor prenatal follow-up and the absence of ultrasound in the third trimester could be great contributors to this complication. This situation is representative of many patients residing in rural areas, where limited access to specialized care delays diagnosis and optimal management.

The diagnosis is based on the association of multiple elements: The absence of the cephalic or podalic pole during vaginal examination The palpation of soft parts (such as the shoulder, clavicle, or scapula), or the senation of the thorax, as well as the high position of the presentation.⁴

In case of misdiagnosis, the shoulder progressively engages the mid pelvis, gets blocked and becomes difficult and nearly impossible to disengage, even with manual intervention. This represents a true mechanical impasse.⁷

The fetal and maternal prognosis depends, directly, on diagnostic precocity and management efficiency. In this case, the quick transfer to a level III maternity unit made an emergency cesarean section possible and avoided further dramatic consequences described in the literature (uterine rupture, massive bleeding or severe fetal trauma fractures, paralysis of the brachial plexus). The successful and smooth extraction of the prolapsed arm and the good neonatal outcome (Apgar 8/9) are proof of the efficient multidisciplinary management of this patient.

The attempts of vaginal delivery, in this particular situation, expose to severe fetal trauma that encompasses fractures (clavicle, humerus), dislocations, or lesions to the brachial plexus. The risk is equally important for the mother given that the extraction maneuvers could lead to the tearing of the lower uterine segment, uterine rupture, intense bleeding or infectious complications.⁸

Current obstetrical practice recommends taking multiple crucial factors into account when managing shoulder presentation: The viability and fetal weight, the suspicion of a uterine rupture, Umbilical cord prolapse, history of cesarean section and the experience of the physician.⁶

Among these criteria, fetal viability remains the key determinant of therapeutic decision.²

At the end of pregnancy, when transverse presentation is diagnosed, it is possible to try an external cephalic version, if conditions are favorable (no contraindications, intact amniotic sac, normal fetal mobility). If the fetal position persists the same, a cesarean section is programmed.⁸

However, if the patient is already in active labor and has an advanced dilation and the shoulder is impacted, an emergency cesarean section remains the only efficient alternative, although the abnormal fetal presentation makes it difficult to extract the fetus. Thus, the recourse to specific maneuvers may be necessary, for example: an internal podalic version followed by breech extraction or widening of the uterine incision (T-shaped incision) may be essential to allow for atraumatic delivery. In extremely rare and severe cases, particularly in case of fetal demise, decapitation may be required.⁹

From a preventive standpoint, this case perfectly illustrates the importance of rigorous antenatal screening, especially during the first trimester. A meticulous clinical evaluation, (Leopold palpation) would suggest the diagnosis of transverse lie, and an ultrasound at 36 weeks of gestation would identify the position of the fetus and confirm the diagnosis, allowing for an optimal therapeutic planification. The prompt transfer coordination and intervention in a specialized center were crucial to avoid a dramatic outcome.

An early screening and diagnosis allow for a well-planned management and prevents the development of an emergency scenario. In the delivery room, careful monitoring of any abnormal progression of labor is vital, and the absence of engagement of a clearly identified presentation should point to a transverse lie.⁴

Conclusion

The neglected shoulder syndrome following a transverse lie is a rare but serious obstetrical emergency. It is often due to late diagnosis or insufficient prenatal monitoring. It leads to a mechanical impasse that is difficult to reverse with an undeniable risk for both the mother and the fetus. This case shows the importance of prenatal screening, position ultrasound in term pregnancies and the quick transfer to an appropriate facility. The Cesarean section is a must and is the cornerstone of treatment. This situation underscores the need for optimal prenatal care and better organization of healthcare, especially in rural areas.

Ethical consideration

Ethical approval and consent to participate were not required.

Consent for publication

Written informed consent was obtained with assurance of anonymity and confidentiality.