Progesterone for Prevention of Miscarriage & Preterm Birth in Women with First Trimester Bleeding: PREEMPT-Trial


      First trimester bleeding is associated with miscarriage and preterm birth for which progesterone has been suggested to improve outcomes. The objective of our study was to evaluate the effect of progesterone treatment throughout pregnancy on preventing miscarriage and preterm birth in pregnancies with first trimester bleeding.

      Study Design

      Multicenter double-blind placebo controlled randomized trial comparing vaginally administered Micronized Progesterone 200mg nightly from presentation until 34weeks of pregnancy with an identically appearing placebo. Subjects with vaginal bleeding and a live intrauterine pregnancy under 14weeks were offered study participation. Multifetal gestations, cervical insufficiency, recurrent pregnancy loss, or bleeding unrelated to placentation were excluded. Primary outcome was the occurrence of a live term pregnancy. Secondary outcomes included adverse maternal and newborn events and time to miscarriage / birth. Chi square analyses were used to compare proportions and Mann-Whitney tests were used to compare time-to-event outcomes


      549 subjects were recruited and randomized of which 16 withdrew or were lost to follow-up leaving 264 subjects in the progesterone group and 269 subjects in the placebo group. Baseline characteristics were comparable in both groups. As compared to subjects in the placebo group, the number of subjects having a live term birth among those in the progesterone group was 197 (74.6%) vs 190 (70.6%), p=0.30, respectively. As compared to subjects in the placebo group, those in the progesterone group had comparable risks of abortion under 20 weeks, 38 (14.4%) vs 43 (16.0%), p=0.94, preterm birth, 27 (10.2%) vs 33 (12.3%), p=0.46, and stillbirth 2 (0.9%) vs 3 (1.3%), p=0.65, respectively. There were no differences in adverse maternal or newborn outcomes, or in time-to-event for miscarriage or birth between the two groups.


      Progesterone prescribed throughout pregnancy is not effective in preventing miscarriage or prematurity in subjects presenting with first trimester vaginal bleeding in context of a live intrauterine pregnancy.
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