Recurrent abortion.

Recurrent spontaneous abortion affects about 0.5% of women. The causes of recurrent abortion are fetal and maternal. Most fetal causes are genetic or chromosomal abnormalities. Most maternal causes are congenital or acquired uterine abnormalities. Controversy exists regarding the possible etiology of immunologic factors and lupus anticoagulant activity as causes of recurrent abortion. Performance of histocompatibility locus antigen typing and immunotherapy do not appear to be cost effective or necessary in couples with recurrent abortion. The use of treatment for the presence of lupus anticoagulant or anticardiolipin antibodies has not been found to be superior to no treatment and must be regarded as investigational.