Forty-six infertile women with a history of diethylstilbestrol (DES) exposure in utero underwent 149 stimulation attempts for in vitro fertilization (IVF). The mean (+/- SE) number of preovulatory oocytes harvested at retrieval and transferred was 3.9 +/- 3.3 (536/138) and 2.6 +/- 1.4 (328/124). When compared with patients with tubal factor infertility and less than or equal to 4 pre-embryos transferred, the clinical pregnancy rate (15.3% versus 22%) was not statistically different. However, the term/ongoing pregnancy rate was significantly lower in the study group (8% versus 16%). Comparison of the IVF outcome with different uterine anomalies as detected by hysterosalpingogram (n = 29) showed a trend for a worse prognosis in women with constrictions and a combination of T-shape and constrictions. It is concluded that implantation and pregnancy outcome are impaired in DES-exposed women after IVF.