Intrauterine donor insemination in single women and lesbian couples: a comparative study of pregnancy rates.

The outcome of intrauterine donor insemination (IUI-DI) with frozen spermatozoa was analysed retrospectively in 675 cycles in single women (n = 122; 536 cycles) and lesbian (n = 35; 139 cycles) couples. The lesbian patients were younger at the initiation of treatment (mean 34.5 years; range 26-44) than the single women (mean 38.5; range 29-47) (P = 0.005). Clinical pregnancy rate was 36% in single women and 57% in lesbians (P < 0.05), the cumulative pregnancy rate after six cycles being 47% and 70% respectively, although the outcome was similar when related to age. The miscarriage rate was higher (35%) in single women than in lesbians (15%; P < 0.05), the rate being independent of maternal age. There were no apparent differences seen between the two groups with respect to the possible effect of parity, duration of infertility, causes of infertility and type of treatment at initiation of treatment; the sole exception was that the age of lesbian women was statistically significantly younger than that of single women (P < 0.005). When corrected for age, the pregnancy rates and complications were lower and higher respectively in single women but these differences did not reach statistical significance. However, the disparity between the treatment outcomes of single women and lesbian patients of similar ages may also reflect the fact that single women are likely to have failed to conceive for a period of time prior to referral to a specialist centre for treatment.