Antinuclear antibody testing in obstetric patients.

OBJECTIVES To assess possible associations between the presence of antinuclear antibodies (ANAs) and pregnancy outcome in order to determine the significance of this test in obstetric practice. METHODS A case-control study was performed on 408 patients admitted to an obstetric high care unit and on whom ANA testing was consecutively performed. The study group consisted of 46 patients who tested positive for ANAs and a control group of 92 patients who tested negative for ANAs. In addition to demographic data, indications for admission and pregnancy outcome were compared between the two groups. RESULTS Of the 46 patients with a positive ANA result, 28 had an antinuclear pattern, 13 an anticytoplasmic pattern and 5 an antinuclear and an anticytoplasmic pattern. No significant differences were observed between the two groups (ANA-positive and negative) with regard to demographic data, indication for admission, clinical and laboratory data, and pregnancy outcome. The patients were also tested for anticardiolipin antibodies, and significantly more patients with severe pre-eclampsia tested positive (24% versus 4.7%, p = 0.01). No difference in HIV status and presence of autoantibodies was found between the two groups. CONCLUSION The presence of ANAs was not associated with adverse pregnancy outcome. Therefore routine patient testing for ANAs in an obstetric high-care unit is not recommended.