By John C. Hobbins, MD

Professor, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora

Dr. Hobbins reports no financial relationships relevant to this field of study.

SYNOPSIS: A recent large multicenter, randomized clinical trial has shown that delivering patients with premature preterm rupture of membranes at 34 weeks, rather than pursuing a watchful waiting approach until 37 weeks, does not afford greater protection against neonatal sepsis.

SOURCE: Morris JM, Roberts CL, Bowen JR, et al; PPROMT Collaboration. Immediate delivery compared with expectant management after preterm pre-labour rupture of membranes close to term (PPROMT trial): A randomised controlled trial. Lancet 2016;387:444-452.

Preterm premature rupture of membranes (PPROM), defined as rupture of membranes prior to 37 weeks, is responsible for about one-third of premature deliveries. When rupture of membranes occurs, decision-making regarding the timing of delivery has been based on weighing the risks of prematurity against the risk to the mother and fetus of ascending infection. To help with this, the American College of Obstetrics and Gynecology (ACOG) published recommendations this year which, admittedly, were based on “limited and inconsistent scientific evidence.”1 Basically, the ACOG Practice Bulletin suggested that if patients had attained 34 menstrual weeks before ROM, they should be delivered.

This recommendation generally has been followed by clinicians, but many have remained skeptical about this 34th week cutoff. To revisit this common management approach, results from a large multi-country, randomized, clinical trial (RCT) were published in Lancet.2 The study involved 65 centers in 11 countries. Patients who were between 34 weeks, 0 days and 36 weeks, 6 days with documented rupture of membranes were randomized to have either immediate delivery or expectant management, including those positive for Group B streptococcus.

Nine hundred twenty-four patients had immediate delivery and 915 were managed expectantly up until 37 weeks, or until there were signs of infection or fetal compromise. Neonatal sepsis was essentially the same, with 23 patients (2%) in the immediate group and 29 patients (3%) in the expectant group (relative risk [RR], 0.8; 95% confidence interval [CI], 0.5-1.3). Composite neonatal morbidity and mortality were similar, with 8% in the immediate group and 7% in the expectant group (RR, 1.2; 95% CI, 0.9-1.6). On the downside, immediate delivery was associated with significantly higher rates of respiratory distress syndrome (RR, 1.6; 95% CI, 1.1-2.3) and need for any type of ventilatory support (RR, 1.4; 95% CI, 1.0-1.8). Also, infants spent more time in the newborn special care unit (4 days vs. 2 days) (P < 0.0001). Mothers in the immediate group had a higher cesarean section rate (26% vs. 19%, 95% CI; 1.2-1.7).

There were some checks in the good column for the immediate group. They had lower rates of antepartum and intrapartum hemorrhage (RR, 0.6; 95% CI, 0.4-0.9), intrapartum fever (RR, 0.4; 95% CI, 0.2-0.9), and need for antibiotics (RR, 0.8; 95% CI, 0.7-1.0). Not surprisingly, the expectant management group had longer maternal hospitalizations (P < 0.0001), since 75% of these patients were managed in the hospital.

COMMENTARY

It has been assumed that once membranes have ruptured, the barrier to bacterial access into the amniotic cavity is removed, exposing the patient to a ticking septic time bomb. However, this study suggests that immediate delivery of patients with PPROM between 34 and 37 weeks does not necessarily prevent neonatal sepsis — the main reason the aggressive approach was adopted. Instead, one is now faced with a significant increase in cesarean section rate, respiratory distress syndrome, and longer stays in the NICU for respiratory support. The cost of longer maternal hospitalization is easily exceeded by the bloated daily costs of supporting babies in the NICU.

So, at least until the next study surfaces, it seems that if avoiding sepsis is our primary goal, watchful waiting in patients with PPROM between 34 and 37 weeks appears to be a viable alternative, and may prove to be even a better one.

REFERENCES

  1. American College of Obstetricians and Gynecologists Committee on Practice Bulletins — Obstetrics. Practice Bulletin No 160 Summary. Premature Rupture of Membranes. Obstet Gynecol 2016;127:192-194.
  2. Morris JM, Roberts CL, Bowen JR, et al; PPROMT Collaboration. Immediate delivery compared with expectant management after preterm pre-labour rupture of membranes close to term (PPROMT trial): A randomised controlled trial. Lancet 2016;387:444-452.