Repeated fetal loss may be a result of a variety of causes. Immunological factors have been implicated in fetal loss, intrauterine growth retardation, preeclampsia, and thrombocytopenia. Anticardiolipin antibodies (ACAs) belong to a family of autoantibodies known as antiphospholipid antibodies. Platelet aggregation and increased coagulation results from the presence of these antibodies, and is believed to contribute to the fetal complications. This article is a review of the physiological implications of ACAs, screening criteria for the presence of ACAs, prevalence rates, diagnostic measures, treatment options, and possible postpartum effects of ACAs. When women with recurrent pregnancy losses present for care, the nurse-midwife needs to be able to discuss possible causes, aspects of diagnosis, and treatment options available. With a better understanding of what these are, the nurse-midwife will be better able to plan care that will promote a positive pregnancy outcome.