Dose-response effect seen, with longer hypothyroidism period tied to higher autism spectrum disorder risk<\/p>\n<\/h3>\n
By Lori Solomon HealthDay Reporter<\/b>
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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<\/em>.<\/p>\n 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.<\/p>\n 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).<\/p>\n “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.”<\/p>\n