Pregnancy and hypothyroidism–what patients have learned
(Important note: STTM is an information-only site based on what many patients have reported or learned in their treatment. Please work with your doctor. The information on these pages is not meant to replace that relationship or guidance, and you agree to that by reading this website. See the Disclaimer.)
I remember when I, Janie, made the phone call to my doctor to find out if I was pregnant. “Yes,” the nurse said, “you are.” And my reaction? OH MY GOSH. I AM PREGNANT! ME!! It was shocking, exhilarating, scary, fun.
Pregnancy: a time of a growing belly, different clothes, new dreams…and a host of physical demands on your body:
… Your breasts increase to prepare for nursing.
… Your body’s blood volume increases to give nutrients to your baby.
… Your heart rate will rise to meet the demands of your increasing blood supply.
… Calorie storage will increase.
… Progesterone and estrogen levels will rise.
And not only will your thyroid gland enlarge slightly, your TSH will raise and thyroid hormones will increase by 50%.
Why does my TSH go up with pregnancy?
As your estrogen levels go up with pregnancy, so does a particular protein called T4-binding globulin (TBG). That, in turn, binds and lowers your thyroid hormones. Your pituitary responds by producing far more TSH (thyroid stimulating hormone) which will increase your FT3 and FT4 to equal things out. Additionally, the placenta secrets high amounts of a hormone called human chorionic gonadotropin (HCG) which also stimulates the thyroid similar to the TSH. That can even cause some women to have symptoms of HYPERthyroidism.
How can I detect if I develop a thyroid problem when I’m pregnant?
Though your thyroid gland will enlarge slightly with pregnancy, it shouldn’t be detectable. But if your thyroid gland is noticeably larger, or you notice far more fatigue than you think you should have, it’s time to suspect you have a thyroid problem and need to talk to your doctor. You could either have HYPOthyroidism, or HYPERthyroidism. Many women end up with Hashimotos disease during or after pregnancy–the autoimmune version of thyroid problems–and some just find themselves with plain ol’ hypothyroidism.
If I am already on thyroid medication for HYPOthyroidism, will I need to increase it when pregnant?
Yes and fairly immediately, say many knowledgeable doctors. Even this study from the New England Journal of Medicine confirms it, since the growing fetus and its tiny brain will need your thyroid hormones for many weeks. It’s only when your baby is about 20 weeks old does it start to use its own thyroid hormones, but demand for your own thyroid hormones will continue until the baby is born. (And this early need is why some mothers outright “become” hypothyroid while pregnant! The demand overwhelms the thyroid!) The need to increase your thyroid hormone medication, whether natural desiccated thyroid or T3-only, occurs because as estrogen increases with pregnancy, so does the binding of thyroid hormones.
Additionally, if you have the autoimmune version of hypothyroidism called Hashimotos, you’ll want to keep a check on adequately treating your hypothyroidism and antibodies, since some experts state that thyroid antibodies cross the human placenta and could attack your baby’s thyroid.
How much do you increase it? That is something you should talk to your doctor about. It may not be much.
P.S. though the above mentioned study refers to Levothyroxine, a growing body of informed thyroid patients know that natural desiccated thyroid, with all five thyroid hormones, has proven over the years to be a much better treatment.
What about iodine when I’m pregnant?
Just as the need for thyroid hormones increases, so does the need for adequate levels of iodine. Many scholarly articles and health organizations recommend this, range from 150 to 250 µg of iodine supplementation. You can work with your doctor on this.
Why natural desiccated thyroid for HYPOthyroidism if I’m pregnant?
Because, say new moms, it will give you and your little one exactly what your own thyroid would be: T4, T3, T2, T1 and calcitonin. You can read about natural desiccated thyroid and how we raise it here, plus there’s more detail in Chapter 2 of the revised STTM book. Even being on T3-only is a big step from T4-only.
How do healthy levels of my thyroid hormones, or the right supplementation, affect my little growing baby?
Even by the late 1800’s, medical professionals knew about the importance of thyroid hormones on the developing brain of the fetus. Since then, numerous animal studies haves supported that knowledge. Your thyroid hormones also positively affect your baby’s nervous system.
What if I’ve given birth and am nursing?
Your own need for good thyroid function (or thyroid medications like natural desiccated thyroid) and iodine still continue when nursing, and is higher than when you are not nursing. Janie, the creator of the Stop the Thyroid Madness movement, was sick, sick, sick when nursing her second and third babies due to undiagnosed hypothyroidism!! You can read her story right here and more in the introduction of the revised STTM book.
Share this information with your doctor.