Contemporary issues for spontaneous abortion. Does recurrent abortion exist?
Most of the time, spontaneous abortion is a random event and represents the natural selection process. Although a recurrent factor may be present and may cause one or more abortions for a given couple, such instances are rare. Well-substantiated causes include parental chromosomal abnormalities (e.g., translocation), antiphospholipid syndrome, PCOD, and maternal age greater than 40 years. Müllerian duplication defects are most likely a cause of pregnancy loss for some women. A growing body of evidence refutes the role of corpus luteum defect as a common cause of recurrent abortion. Other causes are numerically infrequent in occurrence. It is likely that cigarette smoking and alcohol consumption contribute to pregnancy wastage. Although some therapies for the causes listed herein have been proven effective by randomized controlled trials, most have not. Given the excellent outcome demonstrated for most couples with unexplained recurrent abortion in the absence of treatment, it is difficult to recommend unproven therapies, especially if they are invasive and expensive. Instead of examining the environment in which pregnancy has occurred or been planned, clinicians have simply counted the number of spontaneous abortions among couples in an attempt to determine who should be evaluated. The former approach would seem most appropriate and proactive.