Hypothyroidism in Pregnant Women

Thyroid signals have significant influence on brain function. Especially the mother’s thyroid signals, during the first three months, on the developing brain of her unborn child.

If a mother has insufficient thyroid signals, called hypothyroidism, this may contribute to attention deficit/hyperactivity disorder (ADHD), which is the most common neurodevelopmental disorder of children in the U.S. This recent research comes out of NYU Langone Health / NYU School of Medicine.

This new investigation showed:

  • Children whose mothers were diagnosed with hypothyroidism shortly before or during the early stages of pregnancy were 24% more likely to have ADHD than children whose mothers did not have the diagnosis.
  • Boys born to hypothyroid women were four times more vulnerable to ADHD than girls whose mothers had hypothyroidism.
  • Hispanic children born to hypothyroid mothers had the highest risk of any ethnic group studied.


Thyroid health rules the brain.

The Developing Brain

In the first trimester the baby does not yet have its own thyroid to signal it’s developing brain. So it leans on mom.

Once a pregnancy has reached the second trimester, a woman’s hypothyroidism had little effect on her children. By now the fetus has begun to produce its own thyroid hormones and thus is less vulnerable to its mother’s deficiencies.

Thyroid health likely has a much larger role in fetal brain development and behavioral disorders like ADHD than previously understood.

We have known, in the last few decades, that if you suffer with thyroid issues, you are more at risk of a variety of brain issues from brain fog to depression. In my break-through book on endocrine disruptors, Hormone Deception, a great deal of data is presented on the intermingling of thyroid, brain function and behavior, with planet earth’s chemical soup we all now live in.

In Hormone Deception, I wrote about a WHO study where the number of mercury amalgams that a mother had—which are damaging to thyroid and brain function to the developing fetal brain—effected the fetal brain and then the baby’s behavior. The more mercury amalgams mom had in her mouth, the more risk of thyroid and behavioral problems in the baby as it grew into a child.

Mom’s health matters to her unborn child’s future.


Diagnosing Hypothyroidism is Controversial and Nuanced

Even the conservative Medscape journal, supported by big Pharma, has been writing in the last 1.5 years, more and more about the futility of using “only” TSH and even T3 and T4 to give us a complete evaluation of thyroid health.   

Medscape, in a few articles, clearly discussed that these serum numbers are not hard and reliable indicators of what is happening with thyroid signals in peripheral tissues.

In one article they discussed that if a woman has failed numerous fertility interventions, and her thyroid numbers were in normal range…. go ahead… try a “trial” of thyroid replacement to see if this boosts her fertility. They reported that this was working in a number of women.

This kind of medical advice has not often been the norm.

Why would this be happening? Because those numbers don’t pick up all cases of hypothyroidism. And some women who had “normal” appearing thyroid levels in their blood (TSH and T3 and T4 but could not get pregnant with intervention over and over again. Will, finally… get pregnant. Why? These tests don’t pick up all hypothyroidism cases.

So, if you have “hidden” hypothyroid problems that even the blood tests of your own docs can’t pick up, but you get pregnant, your baby’s future, it’s future ability to be able to behave normally and thrive, might be at risk.

That is why functional practitioners do deeper dives.

Did you know that before using lab tests to evaluate thyroid function, old-time doctors used the speed of the Achille’s reflex to evaluate thyroid function. There is a machine that does this. The photomotogram. I had one in my first clinic. I ran thousands of labs along with the evaluation of this machine. And I think the Achille’s reflex picked up more cases of subtle hypothyroidism than our labs. Which of course use normal ranges, not ideal ranges.

The Vulnerable Thyroid

Dr. Barbara Demeneix

The thyroid is very vulnerable to today’s toxic environment. I had Sorbonne scientist, Dr. Barbara Demeneix on my radio show (Dr. Berkson’s Best Health Radio – Toxic Cocktail – Your Child’s Thyroid, Brain & IQ) who talked about the vulnerability of our thyroid tissue to what is in our air, food and water. Dr. Demeneix’s career has been looking at how our air, food and water can harm thyroid health, and what this does to the human brain. She especially discusses mom’s thyroid function effecting fetal brain function in her great book: “Toxic Cocktail: How Chemical Pollution Is Poisoning Our Brains” by Barbara Demeneix.

Dr. David Brownstein

If you listen to several shows with my dear colleague, who is like a brother to me, David Brownstein MD, you can learn about his deeper dives to evaluate thyroid function. David has said that in his practice he sees up to 70% or so of women having hypothyroidism, with a substantial number of these cases not identified by today’s labs. And many of these women going on to get pregnant putting the next generation at risk, unless hypothyroidism is found and addressed..

This all screams out lout for careful monitoring of pregnant women for low thyroid hormone levels. And their children, for signs of ADHD and their own thyroid functioning.

What Other Risks?

Does hypothyroidism—even “silent” hypothyroidism—during pregnancy, raise the risk of other neurodevelopmental disorders, such as epilepsy, cerebral palsy, and difficulties with speech? Probably, but these tests have not been run. But I have a lot of studies in Hormone Deception, which was written 22 years ago, that suggests this.

Dr. Alan Gaby

I remember the story of Dr. Alan Gaby who I asked to share on my radio show. I had heard him mention it at one of his infamous Wright/Gaby seminar marathons that used to the goal of all functional docs to attend.

Alan told of one poor woman who suffered with severe psychiatric issues for many years. She had a file that was pounds thick, in the old days when files were paper. She had every psychiatric diagnosis you could think of. She had been on most psychotropic interventions. None of which helped.

Alan diagnosed her with “subclinical” hypothyroidism, as he tested free T3 and reverse T3. Her free T3 was the low end of normal even though her TSH was spot on. And her reverse T3 was high, which blocks healthy free T3 signals. Even though her TSH was spot on.

Most doctors and even endocrinologists do not run thyroid tests other than TSH. And sometimes T3 and T4. But usually not free T3 or reverse T3.

Her levels suggested “subclinical” hypothyroidism. So Dr. Gaby recommended a touch of thyroid replacement. Within 6 weeks, this woman—with lifelong suffering—had normal mood and finally, normal quality of life.


In my book SEXY BRAIN I give a long list of my deep dive into thyroid testing. But every year we seem to add more. Just this last year I worked with a woman in her mid 70’s that had worked with functional doctors for years, not finding answers to her global inflammation. When we found an elevated thyroid binding globulin and an elevated free T3 antibody, finally fixing this allowed her to be much more pain and depression free.

Our small little thyroid, a bow-tie of a gland at the base of our throat, has a lot to do with our own world-life perceptions and sanity. And it starts in the womb.

Be smart.

Thinking of getting pregnant. Get an in-depth thyroid panel. Today I run it much, much more.
Want to learn about all this? Let’s do a deep dive on the thyroid.
Knowledge is power. (Please pass it on to wanna-be-moms.)
Dr. B.

Maternal Hypothyroidism Increases the Risk of Attention-Deficit Hyperactivity Disorder in the Offspring. American Journal of Perinatology, 2020

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