Persistent Thyroid Hormone Imbalance During Pregnancy Tied to Heightened Autism Risk in Offspring

WEDNESDAY, Nov. 26, 2025 (HealthDay News) — Women with persistent thyroid hormone imbalance across pregnancy may have an increased risk of having children with autism spectrum disorder (ASD), according to a study published online Nov. 25 in the Journal of Clinical Endocrinology & Metabolism.

Leena Elbedour, from Ben-Gurion University of the Negev in Beer-Sheva, Israel, and colleagues examined the association between maternal thyroid dysfunction and ASD risk in offspring. The analysis included data from 51,296 singleton births between January 2011 and December 2017.

The researchers found that the ASD cumulative incidence was similar in the offspring of women with normal and abnormal thyroid function (log-rank P = 0.27). Chronic hypothyroidism only was not significantly associated with ASD (adjusted hazard ratio [aHR], 0.47; 95 percent confidence interval [CI], 0.15 to 1.48), but combined chronic and gestational hypothyroidism was associated with higher ASD risk (aHR, 2.61; 95 percent CI, 1.44 to 4.74). There was a dose-response effect, with a longer hypothyroidism period tied to higher ASD risk (one, two, or three trimesters of exposure: aHRs [95 percent CIs], 1.69 [1.19 to 2.83], 2.39 [1.24 to 5.78], and 3.25 [1.07 to 7.21], respectively).

“We found that while adequately treated chronic thyroid dysfunction was not associated with increased autism risk in offspring, ongoing imbalance across multiple trimesters was,” Idan Menashe, Ph.D., also from Ben-Gurion University, said in a statement. “These findings underscore the need for routine monitoring and timely adjustment of therapy to maintain normal thyroid hormone levels throughout pregnancy.”

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