Luteal phase support for patients undergoing frozen-thawed embryo transfer cycles--the required progesterone dose.

With the recent trend toward single-embryo transfer (ET), cryopreservation of extraneous embryos is becoming increasingly prevalent. Several replacement protocols for frozen-thawed ET exist, with no consensus regarding the dosage or delivery mode of progesterone.Hormonal replacement with only estrogen and progesterone is the most frequently used protocol in women with and without functioning ovaries in our unit. Since August 2005, we have doubled the usual daily dose of progesterone for luteal support due to a high prevalence of patients experiencing withdrawal bleeding 11-13 days after ET. We compared the outcome of frozen-thawed ET cycles using different doses of progesterone for luteal support.While the prevalence of embryos that survived the thawing process was significantly higher in the earlier (69%) as compared to the later period (58%), positive b-hCG pregnancy rates (17.5% vs 44.8%, respectively) and clinical pregnancy rates per transfer (7.9% vs 41.4%, respectively) were significantly higher in the later period.We conclude that high-dose progesterone supplementation in the luteal phase of frozen-thawed ET cycles results in a significantly higher clinical pregnancy rate.