11: 17-hydroxyprogesterone for twin pregnancy: no reduction in prematurity or neonatal morbidity


      To determine whether prophylactic 17-alpha-hydroxyxprogesterone caproate (17P) given to mothers with twin pregnancy will reduce composite neonatal morbidity by decreasing the rate of preterm delivery.

      Study Design

      Placebo-controlled, double-blind, multicenter, randomized clinical trial. Mothers with diamniotic-dichorionic twins were randomized to 17P (250 mg IM) or placebo (castor oil vehicle, 1 mL), starting at 16-23 wks' gestational age (GA), repeated weekly until 34 wks' GA. Sample size 240 mothers (480 babies) was calculated to give 80% power to detect reduction of composite neonatal morbidity from 45% with placebo to 30% with 17P.


      160 mothers were randomized to 17P, 80 to placebo at mean GA 20 wks. Baseline characteristics were similar between the groups. There was no significant difference in composite neonatal morbidity (14% with 17P vs 12% with placebo), or in mean GA at delivery (35.3 wks vs 35.9 wks), delivery <28 wks (2% vs 1%), <32 wks (9% vs 5%), <35 wks (33% vs 26%). There were no perinatal deaths in the 17P group and 3 neonatal deaths in the placebo group, two after withdrawal of life support because of fetal anomalies not discovered prenatally and one attributed to neonatal sepsis.


      Prophylactic administration of 17P did not reduce the rate of preterm delivery or neonatal morbidity. Contrary to our previous report that 17P was associated with an increased risk of midtrimester loss in triplet pregnancies, we found no such association in this trial of twin pregnancies.