Findings Highlight Lone Intervention for Premature Rupture of Membranes

There currently is no effective management strategy or treatment to prolong pregnancy when preterm premature rupture of membranes (PPROM) occurs before 21 weeks of gestation, and fetuses born under such circumstances nearly universally experience pulmonary hypoplasia with grave outcomes. However, the findings of a new systematic review have shown that serial transabdominal amnioinfusion may decrease morbidity and mortality rates associated with PPROM.¹

Researchers examined the results of randomized and observational studies that compared conventional treatment and transabdominal amnioinfusion to conventional treatment alone. Hospital bed rest and prophylactic antibiotic therapy comprised conventional care for all patients with PPROM in all studies analyzed. A total of four observational studies and three randomized controlled trials met inclusion criteria and involved 147 cases and 165 cases, respectively. The gestational age at inclusion varied from 16 weeks to 33 weeks, reported the authors.

Analysis of the observational studies revealed that in participants who received transabdominal amnioinfusion in addition to conventional treatment, the latency period was prolonged by an average of 14.2 days and the rates of perinatal mortality were reduced, compared with those who received conventional treatment alone. In the transabdominal amnioinfusion group, there were also fewer cases of pulmonary hypoplasia.

Meta-analysis of the randomized controlled trials, however, revealed no significant differences between study groups in the latency period, in perinatal mortality rates, or in the rates of pulmonary hypoplasia. The rates of infectious complications, such as amnionitis and chorioamnionitis, however, were lower in the transabdominal amnioinfusion group.

“Despite the gravity of this condition, current obstetrics management has little to offer. Aside from close monitoring for signs of infection or early labor, no obstetrics interventions have demonstrated the ability to reduce morbidity or mortality rate as the result of early PPROM or to address the underlying pathophysiologic processes that cause this condition,” write the authors. The results of this analysis show that transabdominal amnioinfusion may be a promising intervention with beneficial effects. However, there remains too little evidence to make any recommendations about the usefulness of transabdominal amnioinfusion for PPROM, and additional studies are needed.

PPROM is the leading identifiable cause of premature delivery, and prematurity is the cause of 85% of all cases of neonatal morbidity and mortality.^2,3 The primary maternal risk of prolongation of the latency period is infection.

Pertinent Points:
- In cases of preterm premature rupture of membranes (PPROM), transabdominal amnioinfusion may improve perinatal mortality rates and morbidity such as pulmonary hypoplasia.
- Transabdominal amnioinfusion may be associated with prolongation of the latency period, but only observational studies currently support this finding.
- Whether transabdominal amnioinfusion is a valuable intervention in cases of PPROM is a question that requires further investigation.

References:

1. Porat S, Amsalem H, Shah PS, et al. Transabdominal amnioinfusion for premature preterm rupture of membranes: a systematic review and metaanalysis of randomized and abservational studies. Am J Obstet Gynecol. 2012;207:393.e1-11.
2. Mercer B, Milluzzi C, Collin M. Periviable birth at 20 to 26 weeks of gestation: proximate causes, previous obstetric history and recurrence risk. Am J Obstet Gynecol. 2005;193(pt 2):1175-1180.
3. Mercer BM. Preterm premature rupture of the membranes: diagnosis and management. Clin Perinatol. 2004;31:765-782.