A randomized controlled trial of 17-hydroxyprogesterone caproate (17-OHPC) for the prevention of preterm birth in twins


      17-OHPC has been shown to reduce the rate of recurrent preterm birth in singleton gestation. This study was undertaken to evaluate whether 17-OHPC would reduce the rate of preterm birth in twin gestation.

      Study design

      We performed a randomized, double masked, placebo controlled trial in 14 centers. Healthy women with twin gestation and uniformly established gestational age were allocated to either weekly 250 mg intramuscular injections of 17-OHPC, or matching placebo, starting at 16-20 weeks and ending at 35 weeks' gestation. The primary study outcome was delivery prior to 35 weeks. Power was 90% to detect a 1/3 reduction in the primary outcome rate.


      Six hundred sixty one women were randomized. Baseline demographic data were similar in the two study groups including gestational age at randomization, maternal age, race, BMI, parity, prior preterm birth, smoking, marital status, chorionicity as diagnosed by ultrasound, and conception method. Six women (<1%) were lost to follow-up. Primary and selected secondary outcomes are provided in the Table.
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      Treatment with 17-OHPC did not reduce the rate of preterm birth in women with twins.