Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin.

To assess the risk of miscarriage after in-vitro fertilization (IVF) with respect to age, cause of infertility, ovarian morphology and treatment regimen, a retrospective analysis was performed of the first 1060 pregnancies conceived between June 1984 and July 1990 as a result of 7623 IVF cycles. Superovulation induction was achieved with human menopausal gonadotrophin (HMG) and/or purified follicle stimulating hormone (FSH) together with either clomiphene citrate or the gonadotrophin hormone-releasing hormone (GnRH) agonist buserelin, the latter either as a short 'flare' regimen or as a 'long' regimen to induce pituitary desensitization. There were 282 spontaneous abortions (26.6%) and 54 ectopic pregnancies (5.1%). The mean age of women with ongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2 (SD 4.1) years in those who miscarried, which were significantly different (P = 0.008). There was no relation between the miscarriage rate and the indication for IVF. The miscarriage rate was 23.6% in women with normal ovaries compared with 35.8% in those with polycystic ovaries [P = 0.0038, 95% confidence interval (CI) 4.68-23.10%]. There was no difference in the miscarriage rate between treatment with HMG or FSH. Women whose ovaries were normal on ultrasound were just as likely to miscarry if they were treated with clomiphene or with the long buserelin protocol. Those with polycystic ovaries, however, had a significant reduction in the rate of miscarriage when treated with the long buserelin protocol, 20.3% (15/74), compared with clomiphene citrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82-40.09%).