The value of in vitro fertilization for the treatment of unexplained infertility.

In 54 patients referred with the diagnosis of unexplained infertility (UI), the diagnosis was confirmed in 26 (strict UI) (48%). Minimal abnormalities (MA) were found in 19 (35%); 9 (17%) had gross abnormalities and were excluded from analysis. Fifty patients with tubal infertility were randomly assigned to form a control group. Mean age and type of stimulation did not differ in the two groups. Peak follicular estradiol (E2) and terminal follicular E2 patterns were comparable. There was no difference in the mean number of oocytes retrieved per cycle. However, the control group had significantly more preovulatory oocytes: 3.6 +/- 2.0 standard deviations versus 2.8 +/- 2.1 in the overall UI group (strict UI + MA groups) and 2.7 +/- 2.2 in the strict UI group. Significantly more fertilized oocytes per cycle were obtained in the control group (P less than 0.05). The per-cycle and per-embryo transfer (ET) pregnancy rates were 32.4 and 37.3% in the overall UI group and 24 and 24.5% in the control group. The miscarriage rate was 12% in the strict UI group, 22% in the overall UI group, and 25% in the control group. It is concluded that patients with UI constitute a favorable group for in vitro fertilization and ET.