AbstractDebate persists over the value of chromosome analysis of couples with repeated pregnancy loss. Therefore, we studied the records of all patients referred to the Genetics Division at Thomas Jefferson University for repeated pregnancy loss. Couples were divided into three groups according to the reason for evaluation. In group I (two consecutive abortions) significant chromosome abnormalities were found in 1.8% of individuals; in group II (three or more consecutive abortions) 2.3% of individuals had a chromosome abnormality; and in group III (50% fetal loss) 1.8% of persons had abnormal chromosomes. These rates are lower than those reported by others, but are still ten times higher than those expected in the general population and affirm the value of doing a chromosome study in such couples.In addition, we found increased incidence of liveborn offspring with congenital abnormalities in couples evaluated for the above indications, and found a high incidence of a family history of repeated suboptimal pregnancy outcome. The significance of these findings is discussed.