Early progesterone cessation after in vitro fertilization/intracytoplasmic sperm injection: a randomized, controlled trial.

To investigate the effect of stopping progesterone (P) support at week 5 versus week 8 on ongoing pregnancy rate after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).Prospective, randomized, controlled trial.University-affiliated infertility center.A total of 220 patients with intrauterine pregnancy demonstrated by transvaginal ultrasound after IVF/ICSI.Luteal phase support with micronized vaginal P was suspended at week 5 or at week 8.Ongoing pregnancy rate, miscarriage rate, and number of bleeding episodes.Progesterone levels were similar on the day of the first pregnancy ultrasound exam (149 ± 108 vs. 167 ± 115 ng/mL). Significantly more bleeding episodes were observed in the first trimester in the group with early cessation of P supplementation (18.0 ± 2.6 vs. 7.2 ± 1.3 episodes). Miscarriage rates among singleton pregnancies were similar in the two groups (5/80 vs. 6/79).Vaginal P supplementation after IVF/ICSI can be safely withdrawn at 5 weeks' gestation, because cycle outcome was similar to conventional luteal phase support up to 8 weeks of pregnancy.NCT01177904.