Autoimmune Thyroid Dysfunction in the Postpartum Period*

Abstract

The prevalence of thyroid disease was investigated in 460 Caucasian women after delivery. Thyroid microsomal antibodies (MsAb) were found in 44 (9.6%) of the women. These womenappeared to have autoimmune thyroiditis. The changes in MsAb titers followed a predictable patternwith maximal values around 5–7 months postpartum. At this time 20 of these women had transient hypothyroidism and in some this was preceded by a thyrotoxic episode. The extent of postpartumhypothyroidism correlated well with the titers of MsAb in early pregnancy and in the postpartum period. Transient thyrotoxicosis occurred in eight women 5–7 months postpartum. TSHreceptor stimulating antibodies and/or high radioiodine uptake, suggesting Graves’ disease, were detected in four of these women. Thus, after delivery, manifestations of autoimmune thyroid disorders, are remarkably common. Inpatients with autoimmune thyroiditis measurements of MsAb provide a good prognostic marker for thedevelopment of transient hypothyroidism.