17-hydroxyprogesterone caproate for twin pregnancy: a double-blind, randomized clinical trial

We sought to determine whether prophylactic treatment with 17-alpha-hydroxyprogesterone caproate (17Pc) in twin pregnancy will reduce neonatal morbidity (primary outcome) by prolonging pregnancy (secondary outcome).

This was a double-blind, randomized clinical trial. Mothers carrying dichorionic-diamniotic twins were randomly assigned (in a 2:1 ratio) to weekly injections of 250 mg of 17Pc or placebo, starting at 16-24 weeks and continued until 34 weeks.

In all, 160 women were randomized to 17Pc and 80 to placebo. Composite neonatal morbidity occurred with similar frequency in the 17Pc and placebo groups (14% vs 12%, respectively, P = .62). Mean gestational age at delivery was not affected by 17Pc (35.3 vs 35.9 weeks, P = .10), but a 3-day difference in median gestational age favored placebo (P = .02). There were no perinatal deaths with 17Pc and 3 with placebo.

In twin pregnancy, prophylactic treatment with 17Pc did not prolong gestation or reduce neonatal morbidity.