A longitudinal study of thyroid autoantibodies in pregnancy: The importance of test timing

Abstract

Objective Thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TGAb) are frequently measured to investigate thyroid dysfunction in pregnancy. Despite the recognized fall of these autoantibodies in pregnancy, there is limited guidance on the timing of such testing. We assessed optimal test timing of TPOAb/TGAb for the detection of Hashimoto's thyroiditis and post-partum thyroid dysfunction (PPTD). Design Prospective longitudinal study with recruitment in Trimester 1. Patients Healthy women ≤13 weeks' gestation from Mercy Hospital for Women, a tertiary obstetric hospital in Melbourne. Measurements Serum TPOAb, TGAb, TSH and fT4 were measured at Trimester 1 (T1), Trimester 2(T2),..