A randomized clinical trial of daily nonstress testing versus biophysical profile in the management of preterm premature rupture of membranes

Abstract

Objective: Our purpose was to evaluate the ability of 2 different antepartum testing modalities to predict infectious morbidity in patients with preterm premature rupture of membranes.

Study design: During a 36-month period, patients with preterm premature rupture of membranes (at 23 to 34 weeks of gestation) were randomly assigned to either a daily nonstress test or a biophysical profile, after a 24-hour observational period. We used the original scoring system of Manning et al for the biophysical profile, with a score of </=6 considered abnormal. Nonstress test results were considered abnormal if the test was nonreactive or if the patient had late decelerations or significant variable decelerations; abnormal results led to further evaluation with a biophysical profile. Results of the last test before delivery were evaluated to determine whether infectious complications had been predicted.

Results: One hundred thirty-five patients were enrolled in the study. Demographics, pregnancy characteristics, and neonatal outcomes were similar. Neither the daily nonstress test nor the daily biophysical profile had good sensitivity for predicting infectious complications (39.1% and 25.0%, respectively). However, both had good specificity (84.6% and 92.6%, respectively). Positive and negative predictive values were 52.9% and 75.9%, respectively, for the daily nonstress test and 66.7% and 68.4%, respectively, for the daily biophysical profile. Cost was significantly higher in the daily biophysical profile group. Nonstress testing of patients at <28 weeks' gestation generally required a backup biophysical profile.

Conclusion: Neither the daily nonstress test nor the daily biophysical profile had good sensitivity for predicting infectious complications after preterm premature rupture of membranes.