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

Abstract

Our objective was to assess parameters associated with a successful outcome of intrauterine insemination (IUI) using cryopreserved donor sperm. We analyzed 750 consecutive donor IUI cycles undertaken by 363 women in an assisted conception clinic. The main outcome measure was clinical pregnancy. 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 < or = 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 59.9% 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, 23.6% in clomiphene 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. 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.