Women diagnosed with subclinical hypothyroidism before 21 weeks of pregnancy are four times more likely to develop full-blown thyroid disease within five years of giving birth, according to a study published in Thyroid®. ()

What is Subclinical Hypothyroidism

Subclinical hypothyroidism, or a change in the levels of thyroid-stimulating hormone (TSH) that isn’t severe enough to cause symptoms, is especially common during pregnancy, affecting as many as 1 in 4 pregnant people. While subclinical hypothyroidism isn’t inherently dangerous, overt hypothyroidism comes with serious symptoms including fatigue, depression, and heart problems.

‘Higher levels of #thyroid antibodies during #pregnancy increases risk of #hypothyroidism after childbirth. #Autoimmune factors play a role in postpartum thyroid issues. #thyroidhealth’
      

Michael Varner, MD, professor of obstetrics and gynecology in the Spencer Fox Eccles School of Medicine at University of Utah Health, and his coauthors reported that progression to overt hypothyroidism was more common in individuals with thyroid-stimulating hormone levels that were more than twice the normal level.

The investigators found that diagnosis of hypothyroxinemia, a deficiency in the thyroid hormone thyroxine, before 21 weeks of pregnancy was not associated with the development of overt hypothyroidism after delivery.

“Studying the long-term associations of test results, as well as the impacts of our interventions, during pregnancy on the health and well-being of mothers and children is a particularly important aspect of clinical research in perinatal medicine,” Varner says.

“While the parent NICHD Maternal-Fetal Medicine Units Network trials from which our data are derived showed no difference in 5-year neurodevelopmental outcomes in children from prenatal treatment of either subclinical hypothyroidism or hypothyroxinemia, our data lend further evidence to the postpartum time period as a time when autoimmune diseases, in this case, hypothyroidism, are more likely to be present.”

Reference:

1. Progression of Gestational Subclinical Hypothyroidism and Hypothyroxinemia to Overt Hypothyroidism After Pregnancy: Pooled Analysis of Data from Two Randomized Controlled Trials – (https://www.liebertpub.com/doi/10.1089/thy.2023.0616t)

Source-Eurekalert