Aggressive tocolysis does not prolong pregnancy or reduce neonatal morbidity after preterm premature rupture of the membranes

Abstract

Objective: This study was undertaken to evaluate whether aggressive tocolysis improves pregnancy outcome after preterm premature rupture of the membranes (PPROM).

Study design: Retrospective case-control study of patients with PPROM before 34 weeks of gestation, followed by a prospective cohort study with historical controls. The retrospective phase covered 1995 through 1999 when we used tocolysis aggressively. With the use of survival analysis, we compared latency in our cases with 4 published control series in which tocolysis was never used. On the basis of the results, we adopted a new protocol in mid-2000 limiting tocolysis to 48 hours after betamethasone dosing and we conducted a 2-year prospective evaluation of this new protocol.

Results: In the retrospective phase, tocolysis was used in 94% of 130 cases and maintained during 84% of 1162 total antenatal patient-days. There was no difference in latency between our cases and the published controls. One or more complications of tocolysis occurred in 18%. In the prospective study, 43% of 63 patients received tocolytics, but these were used at lower doses and were given during only 7% of 770 patient-days. Latency with this very limited tocolytic regimen (median 4.5 days, interquartile range 2.3 to 14.0) was not significantly different than during the last 24 months of aggressive tocolysis (median 3.8 days, 1.8 to 14 days, P=.16) and there were no differences in neonatal morbidity.

Conclusion: Aggressive tocolysis after PPROM causes significant maternal morbidity, but does not increase latency or decrease neonatal morbidity compared with either very limited tocolysis or no tocolysis at all.