SMFM Statement: Use of 17-alpha hydroxyprogesterone caproate for prevention of recurrent preterm birth.

In late 2019, results from the Progestin's Role in Optimizing Neonatal Gestation (PROLONG) trial were published showing no benefit of weekly injections of 17-alpha hydroxyprogesterone caproate (17-)HPC) from 16-20 weeks of gestation in women with a history of a singleton PTB in reducing the rates of subsequent PTB and neonatal morbidity. The Society for Maternal-Fetal Medicine believes that the differences in these results from the earlier Meis, et al trial, which did show a benefit of 17-OHPC in reducing the rate of spontaneous PTB (sPTB), may be at least partially explained by differences in study populations. SMFM concludes that it is reasonable for providers to use 17-OHPC in women with a profile more representative of the very-high-risk population reported in the Meis trial. For all women at risk of recurrent sPTB, the risk/benefit discussion should incorporate a shared decision-making approach, taking into account the lack of short-term safety concerns but uncertainty regarding benefit.