Preclinical abortions and endometriosis.

A single human chorionic gonadotropin determination was performed in 786 infertile women during the late luteal phase to determine the frequencies of preclinical abortions and whether the frequency was increased in women with endometriosis. Thirty-seven pregnancies (4.7% of cycles) were identified, of which six were classified as preclinical abortions (0.8%). In women with endometriosis, the frequency of preclinical abortions was 0.9% and was not statistically different from other infertile subgroups. This study suggests that preclinical abortions are not cause of infertility in either an infertile population as a whole or in the subgroup of women with endometriosis.