Vaginal delivery in a woman with prune belly syndrome: a case report

Abstract

Prune belly syndrome (PBS) is a rare congenital disorder predominantly affecting males, making cases involving females, and particularly pregnant women, uncommon. A clinical manifestation of PBS is abdominal muscle deficiency, which may contribute to a prolonged second stage of labor (PSSL). To date, only four cases of labor in women with PBS have been reported in the literature: three gave birth by cesarean section (CS) and one by vacuum-assisted vaginal delivery. Whether spontaneous vaginal delivery is achievable in women with PBS and hypoplastic abdominal muscles without the need for instrumental or operative assistance has not yet been described in the literature. In this case report, we describe a successful spontaneous vaginal delivery in a woman with PBS affecting her abdominal muscles, who had a short interpregnancy interval and had previously undergone an emergency CS due to PSSL. This case report suggests that spontaneous vaginal delivery may be feasible in cases with a mild phenotype of PBS. However, vaginal delivery may only be considered in highly selected cases and settings where immediate access to surgical intervention is available.

Introduction

Prune belly syndrome (PBS; also referred to as Eagle-Barrett syndrome or Obrinsky syndrome) is a rare congenital disorder with an incidence varying from 1 in 29,000 to 40,000 live births, with the vast majority of affected patients being male (approximately 95%).¹ The syndrome is characterized by a triad of abnormalities: abdominal muscle deficiency, urinary tract abnormalities, and bilateral cryptorchidism. Additional anomalies may involve the gastrointestinal, musculoskeletal, and cardiopulmonary systems with the prognosis primarily depending on the degree of pulmonary and renal involvement.^1,2 Thus, the phenotype ranges from mild presentations compatible with normal life to severe forms resulting in stillbirth. The etiology of the syndrome remains unknown, but two of the major theories include in utero urethral obstruction3, 4, 5 and primary mesodermal development defects.6, 7, 8

The mechanism of labor is traditionally divided into three stages, with the second stage relying on the interaction of “the three P’s” (power, passage, and passenger). Power combines maternal pushing and uterine contractions generating, intraabdominal pressure to facilitate the passage of the passenger (fetus) through the passage (birth canal). Dysfunction in any of these factors may cause dystocia, and thus abdominal muscle deficiency can prolong the second stage by reducing the effectiveness of power (maternal pushing). However, the relative contribution of maternal pushing versus uterine contractility likely varies between individuals, and the extent to which abdominal muscle deficiency affects labor progression remains uncertain.

When searching the literature, we only found four reported cases of labor in women with PBS.9, 10, 11, 12 The first case report by Hillman et al⁹ described an attempted vaginal delivery in a woman with PBS, where the delivery was assisted by vacuum extraction due to prolonged second stage of labor (PSSL). Moreno et al¹⁰ reported a labor in a woman with PBS affecting the abdominal muscles, who also had severe kyphoscoliosis and restrictive pulmonary insufficiency. Due to abnormal maternal pelvic rotation, a transverse fetal position, and possible intrauterine growth restriction, an elective cesarean section (CS) was performed at 37 weeks’ gestation. Similarly, Morita et al¹¹ described a CS in a woman with PBS and abdominal wall hypoplasia. An elective CS was planned at 37 weeks’ gestation due to concerns about PSSL. However, the woman went into labor at 35 + 2 weeks’ gestation, and an emergency CS was performed.

In this article, we describe a spontaneous vaginal birth after cesarean (VBAC) in a woman with a short interpregnancy interval and PBS affecting the abdominal muscles. Jacobsen et al¹² have previously reported this woman’s first labor, which resulted in an emergency CS due to PSSL.

Case presentation

A 30-year-old woman with PBS was referred to our department at 12 weeks’ gestation for routine prenatal care (Figure). The woman had been diagnosed with PBS as an infant with an absence of the abdominal oblique muscles and thin rectus abdominis muscles, but without other clinically recognized associated anomalies. Her past medical history included asthma, irritable bowel syndrome, and attention deficit hyperactivity disorder. She did not take any regular medication, and her PBS did not result in any severe limitations in her everyday life; she was employed full-time as a social and health care assistant.

Figure.

Timeline of prenatal care, labor, and postpartum period. The interpregnancy interval was 8 months, and there was 17 months between the acute cesarean section and the spontaneous vaginal birth.

Prenatal care

The woman was gravida 3, para 1, with an interpregnancy interval of 8 months, a prior CS, and a surgical abortion 5 years prior to her second pregnancy. The current pregnancy was planned, and there were no reported difficulties with conception. Before pregnancy, she weighed 68 kg and was 163 cm tall (body mass index of 25.6 kg/m²). A first trimester ultrasonography was performed, revealing a normal intrauterine pregnancy with an estimated gestational age of 12 + 1 weeks. The woman’s first labor, at 39 + 2 weeks’ gestation, ended in an emergency CS due to PSSL and maternal exhaustion after being fully dilated for 3 hours with no evident progression.¹² During the current pregnancy, regular ultrasonography was performed at gestational weeks 12, 19, 28, and subsequently every four weeks until delivery. The scans revealed normal fetal development and growth.

The birth plan was discussed with the woman, who expressed fear of CS and preferred trial of labor after cesarean (TOLAC). Our recommendation was an elective CS, given the abdominal muscle deficiency, a history of PSSL, prior CS, and short interpregnancy interval. Danish national guidelines¹³ recommend CS when <18 months since CS due to the increased risk of uterine rupture compared to a longer interval (2.25% and 1.05%¹⁴). After shared decision-making and detailed counseling about the risks, the woman chose to proceed with TOLAC. Intrapartum safeguards were implemented, including continuous fetal monitoring during the active phase of labor and access to immediate surgical intervention.

Pregnancy outcome

The pregnancy was notable for a 7-kg weight gain and Braxton-Hicks contractions from 30 weeks’ gestation but was otherwise unremarkable. At 39 + 6 weeks’ gestation, the woman presented to the maternity ward at our secondary care hospital for assessment after having spontaneous contractions for 12 hours at home. She was in the latent phase, with cervix dilated less than 4 cm and the fetus in cephalic presentation. However, one and a half hours later, the contractions intensified, and the woman was in active labor with cervix dilated to 5 cm; 1 hour later, dilation had progressed to 8 cm. The woman received pain relief through water immersion and nitrous oxide. Labor progressed rapidly, and when the cervix was fully dilated, the midwife performed an amniotomy, releasing clear amniotic fluid. She began pushing four hours after arrival and made good progress. Several complicated variable decelerations were observed on the cardiotocography during the pushing phase; however, a fetal scalp pH of 7.24 indicated no immediate fetal distress. After approximately 40 minutes of pushing, the woman delivered a male infant weighing 3220 g with an Apgar score of 10 at 1 minute. However, the birth was complicated by a third-degree laceration, which was sutured and subsequently followed up during the first postpartum days and in the outpatient clinic after 12 weeks without major complications. The postpartum blood loss was 900 mL primarily from a vaginal tear and ceased after suturing. Despite these complications, the woman was very satisfied with the VBAC.

Discussion

PBS is a rare congenital disorder predominantly affecting males, making cases involving females, and particularly pregnant women, uncommon. Our literature search identified only four case reports discussing labor in women with PBS.9, 10, 11, 12 Two women delivered by CS,^10,11 and two women attempted vaginal delivery. However, both women who attempted vaginal delivery experienced PSSL, leading to an emergency CS¹² and vacuum-assisted delivery,⁹ respectively.

We report a VBAC in a woman with a short interpregnancy interval and PBS affecting the abdominal muscles, who had previously experienced PSSL. To our knowledge, this is the first reported case of a woman with PBS who successfully delivered vaginally without instrumental or operative assistance and without PSSL. Abdominal muscle deficiency may increase the risk of PSSL by reducing the effectiveness of maternal pushing.^9,12 Effective Valsalva maneuvers may contribute to fetal descent, but uterine contractility and maternal positioning also play important roles. In this case, the relatively rapid labor progression suggests that uterine contractions alone may be sufficient to achieve vaginal delivery in some women with abdominal muscle deficiency. However, this hypothesis remains speculative and requires further investigation.

PBS is a heterogenous disorder with a wide spectrum of severity and phenotypic presentation, ranging from partial abdominal muscle deficiency to complete absence of abdominal musculature. The phenotype of the woman described by Morita et al¹¹ appears similar to that of the woman in our case (deficient oblique abdominal muscles and thin rectus abdominis muscles). However, an elective CS was planned due to concerns about PSSL. The phenotype in the case reports by Hillman et al⁹ and Moreno et al¹⁰ was not specified in detail with respect to muscle involvement. However, Hillman et al⁹ reported their case as an overall mild presentation, yet the woman had diminished maternal pushing forces and needed vacuum-assisted delivery. No maternal complications were described in three of the case reports,9, 10, 11 whereas our woman’s first labor by CS was complicated by uterine atony, blood loss of 850 mL and postcesarean wound infection. Table summarizes characteristics and outcomes in the published case reports.9, 10, 11, 12

Table.

Published case reports involving pregnancy and labor in women with PBS (n = 4)

Study	Hillman et al9	Moreno et al10	Morita et al11	Jacobsen et al12
Maternal age and parity	25 years, para 0	25 years, para 0	27 years, para 0	29 years, para 0
PBS phenotype, associated anomalies and comorbidities	Deficient/Absent abdominal musculature Repeated bouts of pneumonia and UTI (suggests urinary stasis or incomplete bladder emptying). Overall mild presentation	Described as “no abdominal muscles,” “hypoplasia of the abdominal muscles” and “absence of abdominal muscles and typical aponeurosis leaflets” Severe congenital kyphoscoliosis, severe restrictive lung impairment and asthma	Abdominal wall dysplasia Thinning of the rectus abdominis muscle (1–2 mm) and significantly hypoplastic or deficient oblique abdominal muscles Fetal hydrops, open bowel resection due to intestinal malrotation and funnel chest surgery	The absence of the abdominal oblique muscles and thin rectus abdominis muscles No associated anomalies, but asthma, irritable bowel syndrome, and attention deficit hyperactivity disorder
Planned delivery and actual delivery, incl. gestational age	Vaginal birth → vacuum-assisted vaginal delivery at 40 + 5 weeks’ gestation	Elective preterm CS at 37 weeks’ gestation	Elective CS was planned at 37 weeks’ gestation, but the patient went into labor at 35 + 2 weeks’ gestation → emergency CS	Vaginal birth → emergency CS at 39 + 1 weeks’ gestation
Mode of delivery decisions	N/A	Due to the maternal and fetal risks (abnormal maternal pelvic rotation, risk of uterine rupture by transverse presentation, and risk of fetal distress/intrauterine growth restriction with fetal weight approximately below the 3rd percentile)	Due to the possibility of PSSL	The existing literature of labor in patients with PBS was presented, but the woman wished to pursue vaginal birth
Labor challenges	PSSL and need for vacuum-assisted vaginal delivery secondary to diminished maternal pushing forces	The type of anesthesia, due to the anatomical deformity of the spine and restrictive pulmonary insufficiency and asthma	Preterm labor	PSSL (fully dilated for 3 hours) + maternal exhaustion
Maternal outcome	Uncomplicated postpartum course	The absence of complications during the puerperium	No obstetric complications and no major postoperative complications	Uterine atony after delivery, blood loss of 850 mL and postcesarean wound infection
Fetal outcome	2975 g, Apgar scores of 9 and 9 at 1 and 5 minutes, respectively. No anatomical abnormalities	2370 g, length of 46 cm, Apgar score 8/9, no malformations, but respiratory distress	2370 g. Admitted to the neonatal intensive care unit due to preterm labor and transient hyperpnea	Full Apgar score after 1 min

CS, cesarean section; PBS, prune belly syndrome; PSSL, prolonged second stage of labor.

The choice of delivery method in women with PBS should be individualized and based on the severity of abdominal muscle deficiency, associated anomalies, and fetal and maternal factors. Although a single case cannot establish general recommendations, this case report suggests that vaginal delivery, including VBAC, may be feasible in carefully selected cases with a mild phenotype of PBS. However, the potential feasibility of vaginal delivery must be weighed against significant obstetric risks. Women with PBS should be thoroughly counseled regarding the risk of PSSL and the potential need for conversion to emergency CS^11,12 or vacuum-assisted delivery.⁹ Importantly, the apparent success of VBAC should not obscure the fact that the woman experienced substantial blood loss and perineal trauma. These maternal complications illustrate that even when vaginal delivery is achievable, it may still be associated with significant morbidity. Therefore, vaginal delivery may only be considered in highly selected cases and settings where immediate access to surgical intervention is available.

Patient consent

The patient has given informed consent.

CARE guideline adherence

This case report was prepared in accordance with the CARE guidelines.

CRediT authorship contribution statement

Sabine Yvonne Overby Salomonsen: Writing – review & editing, Writing – original draft. Richard Farlie: Writing – review & editing, Supervision. Kirsten Slot Bünemann: Writing – review & editing, Supervision.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.