The prevalence of antithyroid autoantibodies in pregnant women ranges between 6 and 10%, like in the general population. PPT, a syndrome of transient or permanent thyroid dysfunction occurring in the first year after delivery, is associated with the presence of TPO in gestation. The prevalence varies from 5 to 10%, with higher frequency in patients with DM1. The aim of this study is to estimate TPO frequency during gestation and its relationship with PPT in a group of women with GDM.
Methods: GDM was diagnosed in a cohort of 1700 pregnant women (mean age 32.7±6.5 years; mean gestational week: 26.2±5.1), excluded patients with previous thyroid dysfunction. In 1053 patients (60.3%) a follow-up of thyroid function after delivery was performed (3.5±3.3 months).
Results: The 22.7% of the patients were TPO positive (>11.9 U/ml). A clear association between the presence of TPO and recurrent pregnancy loss (≥3 miscarriages) was found (RR: 2.41; CI 95%: 1.174.97). The prevalence of hypothyroxinemia in the cohort was 5.1%, regardless of autoantibodies levels. Positive TPO frequency postpartum was 39.9%. Women with positive TPO during pregnancy had a greater risk to maintain a positive titer in postpartum (RR: 2.63; CI 95%: 2.303.01). The PPT prevalence in pregnant with positive TPO during gestation was higher (RR: 3.76; CI95%: 2.615.42).
Conclusions: Considering the high prevalence of positive TPO in women with GDM and the increased risk of developing PPT in this group, a screening of thyroid function during pregnancy and a postpartum follow-up is recommended in this women. There is a significant association between the presence of thyroid autoimmunity and a higher miscarriage rate.
03 - 07 May 2008
European Society of Endocrinology