Anti-thyroid antibodies and antiphospholipid syndrome: evidence of reduced fecundity and of poor pregnancy outcome in recurrent spontaneous aborters.

PROBLEM: To determine the presence of anti-thyroid antibodies in patients with primary antiphospholipid syndrome (APS) [antiphospholipid antibodies (aPL) + recurrent spontaneous abortion (RSA)], compare APS alone with APS and thyroid autoimmunity for fecundity and for pregnancy outcome. METHOD OF STUDY: A total of 203 non-pregnant women affected with primary APS were evaluated for anti-thyroid antibodies; 162 non-pregnant women affected with RSA and thyroid autoimmunity alone served as controls. RESULTS: Anti-thyroid antibodies were found in 27% of APS patients studied. Patients with aPL alone had higher percentages of spontaneous pregnancies (P < 0.0001) and live births (P = 0.0003), when compared with patients positive for anti-thyroid antibodies alone or with aPL. CONCLUSIONS: Thyroid autoimmunity is frequently present in APS recurrent aborters and is often associated with either reduced fecundity or with poor pregnancy outcome. Thyroid antibodies should always be evaluated in women with RSA including those with aPL.