Effect of progesterone supplementation in early pregnancy on the pregnancy outcome after in vitro fertilization.

A retrospective cohort study was performed to evaluate IVF clinical pregnancy rates and livebirth rates between patients receiving progesterone supplementation through the first trimester of pregnancy (first trimester protocol) at 12 weeks vs. discontinuation after a positive beta-hCG test 2 weeks after retrieval (luteal protocol) at 4 weeks of pregnancy. A similar rate of clinical pregnancies occurred at 7 weeks (81.8% luteal protocol vs. 85.8% first trimester protocol; P=.49) and for livebirth rates (76.8% luteal protocol vs. 75.0% first trimester protocol; P=.80), but a trend toward a higher rate of pregnancy loss after 7 weeks in the first trimester protocol group occurred (15.5% vs. 4.4%; P=.06), indicating that first trimester progesterone supplementation may support early pregnancy through 7 weeks by delaying miscarriage but does not improve livebirth rates.