We’ve all done it. Stripping the membranes is an old, familiar method of separating the fetal membranes from the lower uterine segment, which is thought to trigger the local production of prostaglandins and hasten the start of contractions.1
Membrane stripping is a focus of controversy when it comes to the issue of group B streptococcus (GBS). This article looks at the literature on the subject and presents a recent legal case in which a woman colonized with GBS claimed membrane stripping was the proximate cause of her infant’s death. In the case, experts for the plaintiff testified that membrane sweeping in a women colonized with GBS is below the standard of care, despite evidence to the contrary. The case, which involved a 2-week jury trial, resulted in a defense verdict.
The legal case
A 22-year-old primigravida presented at just over 39 weeks’ gestation, reporting spontaneous rupture of membranes 1 hour earlier.
IUGR and Group B strep
Her antenatal course had been complicated by intrauterine growth restriction (IUGR), detected by ultrasound at 34 weeks’ gestation. Because of the IUGR, the fetus was being evaluated twice weekly with nonstress tests and amniotic fluid measurements. At 35 weeks, testing for GBS colonization was positive. At 37 weeks, the membranes were stripped to facilitate cervical ripening because of the diagnosed IUGR.
On admission, she was noted to be afebrile with stable vital signs. She was given antibiotics for the GBS and examined. The membranes were grossly ruptured, with clear fluid pooling in the vagina; the cervix was dilated 3 cm with 80% effacement; and the fetus was at –1 to –2 station.
Although the woman was noted to be contracting every 2 minutes, she was barely aware of the contractions. The fetal heart tracing was initially reassuring, with good variability and no decelerations. She was allowed to walk around for 30 minutes.
Sudden fetal bradycardia
Shortly after the patient was placed back on the fetal heart rate monitor, 52 minutes after her initial presentation and approximately 2 hours after rupture of membranes, a marked and sudden fetal bradycardia was noted.
Emergent cesarean section was performed with a low transverse incision. Eighteen minutes after the onset of the bradycardia, a male infant weighing 3,510 g was delivered, with Apgar scores of 0, 2, and 0, at 1, 5, and 10 minutes, respectively. The umbilical cord arterial pH was 6.97. Pediatricians tried to resuscitate the baby, but intubation revealed immediate return of bright red blood. Despite aggressive intervention, including CPR, respiratory support, antibiotics, and inotropic agents, the infant died at 1 hour of life.
Cause of death: GBS pneumonia
An autopsy revealed bilateral massive consolidation of the lungs due to hemorrhagic bronchopneumonia. Tissue and blood cultures of the spleen, lung, and placenta all grew GBS, as did umbilical cord blood cultures. The cause of death: respiratory failure due to overwhelming GBS pneumonia.
The mother’s postpartum course was complicated by a fever of 100.8°F on the second postoperative day, for which she was treated with intravenous ampicillin, gentamicin, and clindamycin. She was discharged home on the 4th postoperative day.
“Data insufficient” for or against
Many practitioners strip the membranes at term to keep patients from passing their due dates. When the membranes are stripped at 40 weeks’ gestation, two thirds of women enter spontaneous labor within 72 hours; without membrane stripping, only one third of women do.2 The strategy also decreases the chance that pregnancies will go past 42 weeks’ gestation.3
Even more important, studies have found membrane stripping to be safe.3-5 The risk of maternal and neonatal infections does not increase with the procedure, according to a Cochrane Review of 2,797 women in 22 different studies.5
The latest statement on the subject from the American College of Obstetricians and Gynecologists (ACOG) is a Committee Opinion published in December 2002—which came after the neonatal death in this case. It says the risks of membrane stripping in women colonized with GBS “have not been investigated in well-designed prospective studies. Therefore, data are insufficient to encourage or discourage this practice in women known to be GBS-colonized.”6
The main witnesses for the plaintiff were a perinatologist and an obstetrician who specializes in infectious diseases. They opined that the infant’s death was caused by the membrane stripping, given that the mother was known to be colonized with GBS.