Objective: To compare cryopreserved ET pregnancy rates in subjects receiving either sublingual parenteral P.
Design: Matched follow-up study.
Setting: University-based assisted reproduction program.
Patients: 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.
Interventions: Cryopreserved embryos were thawed and transferred in all patients in an identical manner independent of the route of P administration.
Main outcome measures: Clinical and ongoing pregnancy rates.
Results: 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 chi 2 test revealed no significant differences in either clinical or ongoing pregnancy rates according to the route of P administration.
Conclusions: 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.