Follicular dominance on the fifth day of controlled ovarian stimulation reduces implantation in long down-regulated ICSI cycles

ObjectiveTo determine if follicular dominance on the fifth day of controlled ovarian stimulation (COS) predicts implantation rates in down-regulated intracytoplasmic sperm injection (ICSI) cycles.Study designOne hundred and sixty-two consecutive women undergoing ICSI treatment with long down-regulation and recombinant follicle-stimulating hormone injections were included in a prospective cohort analysis. The clinical pregnancy and implantation rates per transfer were compared between two groups, one with and the other without follicular dominance detected by ultrasound on the fifth day of COS.ResultsThere was no significant difference between the groups regarding the number of good quality embryos transferred, but clinical pregnancy and implantation rate per transfer were higher in group with follicular synchrony.ConclusionsFollicular dominance on COS day 5 results in reduced implantation rates after ICSI.