Habitual abortion: causes, diagnosis, and treatment

Habitual abortion is defined as three or more consecutive pregnancy losses before 20 weeks of gestation and affects 1% of couples trying to conceive. It is a heterogeneous condition with a number of possible underlying causes: uterine, infectious, genetic, thrombophilic, endocrine, metabolic, immunologic, and environmental. Some of these causes are overdiagnosed because of the different methodologies employed. Over the past few years, attention has been paid to the role of infection (bacterial vaginosis and chlamydial infection) in the etiology of habitual abortion, but studies determining the role of intervention in improving pregnancy outcome are needed. Controversy surrounds the treatment of the different causes of habitual abortion. This is related to problems such as the size of the studies and the different methodologies that have been used in treatment and patient selection. To overcome this, large randomized controlled studies are necessary. Despite the various investigations, the etiology of recurrent abortions remains unknown in about half of all cases. For these individuals, psychologic support and reassurance, rather empirical treatment, are recommended. © 2003 Elsevier Science B.V. All rights reserved.