Risk Factors for Postpartum Thyroid Dysfunction in Euthyroid Women Prior to Pregnancy

Thyroid dysfunction is common during the postpartum and the predisposing factors for its development are considered specific for the population studied. The aim of this study was to evaluate the risk factors for the occurrence of postpartum thyroid dysfunction (PPTD) in euthyroid women prior to pregnancy.

Forty-five women with PPTD and 55 age-matched euthyroid postpartum women from Plovdiv, Bulgaria were included in the study. TSH, FT4, FT3, TPOAb, TgAb, TRAb were measured and ultrasound evaluation of the thyroid was performed in the first trimester of pregnancy and during the postpartum.

The study found higher risk of developing PPTD in women with family history of thyroid disease (OR 4.42; 95% CI 1.87,10.43), smokers (OR 4.01; 95% CI 1.72,9.35), personal history of autoimmune thyroid disease (OR 5.37; 95% CI 1.15,28.53), positive TPOAb (OR 18.12; 95% CI 4.93,66.65) and thyroid US hypoechogenicity during early pregnancy (OR 6.39; 95% CI 2.53,16.12) and those who needed levothyroxine during pregnancy (OR 3.69; 95% CI 1.28,10.61). BMI before pregnancy was significantly lower in women with PPTD than in euthyroid postpartum women (22.80±0.55 vs 26.25±0.97, p=0.013). The multivariate logistic regression analysis identified as most important independent risk factors for PPTD occurrence the TPOAb positivity during early pregnancy, family history of thyroid disease, smoking and lower BMI before pregnancy.

Our data suggest that in the population studied several factors are associated with an increased risk of PPTD and screening for thyroid disorders among those women can be beneficial.