A total of 199 patients (412 consecutive cycles) were treated by oocyte-embryo donation in 336 replacement cycles. Of these, 296 involved intra-uterine embryo transfers, 38 zygote intra-Fallopian transfers (ZIFT) and two gamete intra-Fallopian transfers (GIFT). Of the 336 replacements, 244 (73%) constituted transfers of fresh concepti and 92 (27%) of frozen-thawed ones. A total of 85 pregnancies were achieved of which 16 ended in preclinical abortions, giving a clinical pregnancy rate of 34.7% per patient, 20.5% per transfer and a take-home baby rate of 29.1% per patient. The pregnancy rate was significantly higher (P less than 0.05) following fresh gamete or embryo replacement (23%; 56/244) than following that of frozen-thawed embryos (14.1%; 13/92). No significant difference was observed when intra-Fallopian replacement was applied (27.5%; 11/40) as opposed to intra-uterine (19.6%; 58/296). Ovarian function was not found to be of significant importance to the achievement of pregnancies after oocyte donation since comparable pregnancy rates per replacement and per started cycle were obtained in patients with ovarian failure and in those with functional ovaries (19% and 15.4%; 24.2% and 20.2% respectively). Comparison of the implantation and abortion rates between these two groups did not reveal any significant difference (11.1% and 11.1% versus 14.8% and 16.6%). The highest pregnancy rate among patients with ovarian failure was observed in those with primary ovarian failure (26.4%; 14/53), while the lowest was among women who had received chemotherapy and/or radiotherapy (9%; 1/11).(ABSTRACT TRUNCATED AT 250 WORDS)