A new study has found that women who have ongoing thyroid hormone problems during pregnancy may have a higher chance of giving birth to a child later diagnosed with autism.
The study was published in The Journal of Clinical Endocrinology & Metabolism and adds to growing evidence that the mother’s thyroid health plays a major role in the baby’s brain development.
The thyroid is a small gland in the neck that produces hormones that help control many important functions in the body, including growth, energy use, and brain development. During pregnancy, the baby depends almost completely on the mother’s thyroid hormones in the early stages.
These hormones help guide the growth of the baby’s brain and nervous system. When thyroid hormone levels become too high or too low, the imbalance can disrupt this delicate process.
Autism spectrum disorder, also known as ASD, affects how a person communicates, socializes, and understands the world. It is a complex condition with many possible causes, including genetics, environmental factors, and biological influences during pregnancy.
Scientists have long suspected that thyroid hormones might play a role, and this new research strengthens that idea.
The study followed more than 51,000 births and looked at how thyroid hormone levels changed throughout pregnancy. The researchers focused on whether the mothers had normal levels, temporary imbalance, or imbalance that continued across several trimesters. They found a clear pattern.
When a woman’s thyroid hormones were well controlled and treated properly, there was no increased risk of having a child with autism. However, when the imbalance lasted across multiple trimesters, the risk of autism increased.
Dr. Idan Menashe of Ben-Gurion University in Israel, one of the study’s authors, explained that the key issue is the length of time the thyroid remains unbalanced. A short-term imbalance, if corrected quickly, appears not to cause long-term harm.
But when the imbalance continues for months, the developing baby may receive the wrong levels of thyroid hormones during critical stages of brain development. This may increase the chance of future developmental differences, including autism.
The study also found what researchers call a “dose-response pattern.” This means that the more trimesters affected by thyroid imbalance, the higher the autism risk became. For example, if a mother had thyroid problems in only one trimester, the risk increased slightly.
If the imbalance continued into two or all three trimesters, the risk was stronger. This pattern strengthens the evidence that thyroid hormones play an important role in fetal brain development.
The findings highlight the importance of regular thyroid testing during pregnancy. Thyroid problems are common, especially in women, and many women may not know they have an imbalance until they are tested.
Simple blood tests can monitor thyroid hormone levels, and treatment is usually safe and effective. Doctors often use medication to correct low thyroid hormone levels, and it can be adjusted throughout pregnancy to keep levels stable.
This research suggests that catching thyroid problems early and treating them consistently may help lower the risk of autism related to hormonal imbalance.
It does not mean thyroid problems directly cause autism, nor does it mean every child born to a mother with thyroid issues will have autism. Autism has many different causes, and thyroid imbalance is only one potential factor.
When reviewing the study’s results, it is important to understand what the findings do and do not show. The study does not claim that thyroid imbalance alone causes autism, only that it may increase the risk when it continues untreated for long periods.
The study also cannot explain why some babies are more sensitive than others or how genes interact with thyroid hormones. More research is needed to understand the full picture.
Still, the large size of the study—more than 51,000 births—gives the results strength. The clear pattern of higher risk with more trimesters affected supports the idea that stable thyroid hormone levels are important for the baby’s developing brain.
From a medical standpoint, the study reinforces the importance of routine monitoring, early treatment, and careful follow-up for thyroid disorders during pregnancy.
As with all scientific research, these findings should be used to improve care, not to create fear. Thyroid problems can be managed, and most women with thyroid issues go on to have healthy pregnancies and healthy children. The study simply encourages awareness and early action, which can help protect both mother and baby.
If you care about autism, please read studies about a new cause of autism, and cats may help decrease anxiety for kids with autism.
For more information about health, please see recent studies about vitamin D that may hold the clue to more autism, and results showing strange eating habits may signal autism.
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