Antibodies to beta 2-glycoprotein I and prothrombin in habitual abortion

Objective: To determine the occurrence of antibodies to beta 2-glycoprotein I (beta 2-GP-I) and prothrombin in women with histories of habitual abortions when pregnant and nonpregnant. Design: Antibodies to beta 2-GP-I and prothrombin were measured by ELISA using irradiated polystyrene plates in 43 women with habitual abortions and 22 healthy controls. Setting: Departments I and II of Obstetrics and Gynecology, University Central Hospital of Helsinki. Patient(s): Twenty-two women of the habitual abortion patients had never delivered (primary aborters) and 21 had delivered at least one living child before miscarriage (secondary aborters). Intervention(s): Venous blood samples were collected before and during pregnancy. Main Outcome Measure(s): Immunoglobulin G class antibodies to beta 2-GP-I and prothrombin. Result(s): The secondary aborters showed higher levels of antibodies to prothrombin than the primary aborters when both pregnant and nonpregnant and also showed higher levels of antiprothrombin antibodies than the controls when pregnant. No such differences were found in levels of antibodies to beta 2-GP-I. The habitual abortion patients showed a tendency toward higher levels of these autoantibodies when pregnant than when nonpregnant. Gestational diabetes was more common among the antibody-positive habitual abortion patients than among the antibody-negative patients. Conclusion(s): Increased levels of antiprothrombin antibodies were associated with secondary abortions. Elevated levels of antibodies to beta 2-GP-I and prothrombin often were found in habitual abortion patients with gestational diabetes.