Progesterone offers ‘no benefit’ to women with first-trimest
A multicenter, double-blind, randomized study - The PREEMPT trial — conducted between 2016 and 2020 — compared 200 mg micronized progesterone, vaginally administered nightly from presentation to 34 weeks’ gestation, and a placebo that appeared identical to the study drug. The trial included women with vaginal bleeding and live intrauterine pregnancy at less than 14 weeks’ gestation, and it excluded women with multifetal gestations, recurrent pregnancy losses, cervical insufficiency or bleeding unrelated to placentation.

The primary outcome was the occurrence of live term pregnancy, and secondary outcomes included adverse events for mothers and newborns and time to miscarriage or birth. According to the researchers, 264 patients were included in the progesterone group and 269 patients received a placebo. Baseline characteristics were similar between the two study arms.

Results showed that the percentage of patients with a live term birth was 74.6% in the progesterone group and 70.6% in the placebo group. The two groups had comparable risks for abortion at less than 20 weeks (14.4% vs. 16%), preterm birth (10.2% vs. 12.3%) and stillbirth (0.9% vs. 1.3%). There is no benefit to prescribing progesterone to patients who present with first trimester bleeding.