Methods
For the interventional study participants, the administration of vaginal
progesterone was started between 16+0 and
19+6 weeks of gestation and discontinued at 34 weeks
of gestation or at the time of delivery, rupture of membranes, or
massive uterine bleeding, whichever occurred first. We investigated
obstetric and neonatal outcomes among the study participants and
compared them with outcomes of the historical control group
participants.