Success of intrauterine insemination using cryopreserved donor sperm is related to the age of the woman and the number of preovulatory follicles

Abstract

Objective: Our objective was to assess parameters associated with a successful outcome of intrauterine insemination (IUI) using cryopreserved donor sperm. Design: We analyzed 750 consecutive donor IUI cycles undertaken by 363 women in an assisted conception clinic. The main outcome measure was clinical pregnancy. Results: IUI was performed in 94.7% of the 750 IUI treatment cycles commenced and 180 clinical pregnancies occurred. The clinical pregnancy rate per cycle was 26.4%. The rate was significantly related to the patient's age (30.5% for age ≤35 years and 18.1% for age >.35 years; P < 0.006) and whether there was one or more than one preovulatory follicles [20.9, 34.4, and 31.5% for one, two, and three or four follicles with a mean diameter of 14 or more mm at the time of human chorionic gonadotropin (hCG) administration: P = 0.006]. Two to four preovulatory follicles were present in 12.6% of the natural cycles, 43.6% of clomiphene citrate or tamoxifen, and 59.0% of gonadotropin stimulated cycles. The difference in the number of preovulatory follicles between stimulated and unstimulated cycles was highly significant (P < 0.0001). Pregnancy rates were 29.9% in gonadotropin-stimulated cycles, 23.6% in clomiphene citrate- or tamoxifen-stimulated cycles, and 20.1% in unstimulated cycles. The difference in pregnancy rates between gonadotropin-stimulated and natural cycles was significant (P = 0.038). Cycle fecundity rates were not significantly affected by the number of previous treatment cycles, duration of infertility, gravidity and parity of the patient, presence of a spontaneous luteinizing hormone (LH) surge before the administration of hCG, or number of motile sperm in the insemination specimen. Conclusions: Success of IUI using cryopreserved donor sperm is related to the age of the women and whether there is one or more than one preovulatory follicles.