LAUSR

The objective of this commentary is to describe the background, rationale, and methods of the PROLONG (Progestin's Role in Optimizing Neonatal Gestation) trial, which is a multicenter, multinational, placebo-controlled, randomized clinical trial (RCT) designed to assess the safety and efficacy of Makena (hydroxyprogesterone caproate injection, 250 mg/mL) in reducing the risk of preterm birth (PTB) and neonatal morbidity/mortality in women pregnant with a singleton gestation who had a previous singleton spontaneous PTB. The total sample size of the RCT will include 1,707 women. The trial has two coprimary outcomes: PTB less than 35 weeks and a composite neonatal morbidity and mortality index. This study sample size will provide 90% power to assess for a 35% reduction in neonatal morbidity and mortality. Secondary outcomes will include 2-year follow-up of infants. The trial is ongoing and targeted to complete recruitment in 2018.