The effectiveness of sublingual progesterone administration during cryopreserved embryo transfer cycles: results of a matched follow-up study

To compare cryopreserved ET pregnancy rates in subjects receiving either sublingual or parenteral P. Matched follow-up study. University-based assisted reproduction program. Women undergoing cryopreserved ET between January 1993, and December 1994. Cases received a hormone replacement protocol containing oral E2 and sublingual P and controls received a hormone replacement protocol containing oral E2 and parenteral P. Cases and controls were matched one-to-one according to age, number of embryos transferred, embryo grade, and route of ET. Cryopreserved embryos were thawed and transferred in all patients in an identical manner independent of the route of P administration. Clinical and ongoing pregnancy rates. Of 61 ET cycles performed in the sublingual P group, there were 16 clinical pregnancies (26.2%) and 12 ongoing pregnancies (19.7%). Of the 61 ET cycles in the parenteral P group, there were 14 clinical pregnancies (23.0%) and 11 ongoing pregnancies (18.0%). A χ2 test revealed no significant differences in either clinical or ongoing pregnancy rates according to the route of P administration. This data suggests that sublingual P administration is an effective alternative to parenteral P administration in preparing the endometrium for the implantation of cryopreserved embryos.