PREGNANCY RATES IN A DONOR SPERM PROGRAM USING CRYOPRESERVATION - EFFECTS OF TOTAL NUMBER OF MOTILE SPERM INSEMINATED AND OF A PROCEDURE TOCONCENTRATE SPERM

Objective-To determine the relationship between the total number of mo tile sperm per insemination (TMSI) and pregnancy rates in a donor inse mination program. To determine the effect of sperm concentration and r esultant increase of TMSI on pregnancy rates. Design-Retrospective ana lysis of pregnancy rates. Setting-University hospital with tertiary se rvice. Patients-179 women undergoing donor insemination. Interventions -None. Main Outcome Measures-Calculation of pregnancy rates according to TMSI. Results-The pregnancy rate with insemination of thawed donor sperm increases when the TMSI of unconcentrated sperm is greater than or equal to 80 x 10(6). Pregnancy rates with previously concentrated s perm are as good as or better than rates of unconcentrated specimens. Conclusion-TSMI is important in determining pregnancy rates in donor i nsemination programs, and concentration of sperm prior to freezing may enhance pregnancy rates by increasing the TMSI.