TERBUTALINE PUMP MAINTENANCE THERAPY FOR PREVENTION OF PRETERM DELIVERY - A DOUBLE-BLIND TRIAL

OBJECTIVE: This study's aim was to determine whether maintenance thera py with terbutaline administered by pump prolongs gestation in women a fter treatment with intravenous magnesium sulfate tocolysis for suspec ted preterm labor. STUDY DESIGN: Consenting women with a singleton ges tation and intact membranes who had uterine contractions and >1 cm cer vical dilation, 80% effacement, or progressive cervical change and who se contractions were successfully arrested with intravenous magnesium were randomly assigned to receive either terbutaline or normal saline solution placebo by subcutaneous infusion pump. Pump therapy was admin istered with a standardized protocol. Pump therapy was discontinued an d parenteral magnesium was resumed if recurrent preterm labor develope d while women were on the therapeutic regimen at <34 weeks' gestation and no contraindication far tocolysis existed. If recurrent labor was arrested, pump therapy was restarted according to the original treatme nt group. A sample size of 48 women was required to detect a 2-week in tergroup difference in mean time to delivery. Analyses were based on i ntent to treat. RESULTS: Fifty-two women received terbutaline (n = 24) or placebo (n = 28). At random assignment the groups were similar wit h respect to age, race, parity, previous preterm delivery, gestational age, and cervical examination. Overall there was a 1-day difference i n mean time to delivery between the groups (terbutaline 29 +/- 22 days and placebo 28 +/- 23 days, P = .78). There were no differences in th e rates of preterm delivery at <34 and <37 weeks' gestation. Neonatal outcomes were similar. CONCLUSIONS: Maintenance terbutaline therapy ad ministered by pump does not prolong gestation in women successfully tr eated for suspected preterm labor.