Maternal and Infant Health Program Maternal and Infant Health Program

  SLC area: (801) 273-2871

  SLC area: (801) 274-0674

  Maternal and Infant Health Program
  P.O. Box 142002
  Salt Lake City UT

Answers to Your Questions About Hypothyroidism and Pregnancy

What is Hypothyroidism?

The thyroid is a small gland located in your neck that produces an important hormone for controlling growth, heat production, and the ability to get pregnant. If the thyroid gland produces too little thyroid hormone, a medical condition called hypothyroidism occurs.

Hypothyroidism occurs in about 4-17% of women during their childbearing years. Low thyroid hormone levels are concerning because if untreated, they can cause problems in pregnancy and your baby’s development.

This article answers questions about hypothyroidism during pregnancy. It should not replace the advice of a physician or certified nurse midwife.

My health care provider told me that I have hypothyroidism. Is there anything special I need to do now that I am pregnant?

  • See your doctor or midwife as soon as you find out you are pregnant, or at least by 10 weeks of pregnancy. Ask how he or she plans to treat your hypothyroidism during pregnancy.
  • Try not to worry! With proper care and treatment, you have every chance of having a healthy pregnancy and birth.
  • Take your thyroid medication each day as directed. Be careful not to miss a dose.
  • Have your blood thyroid levels (TSH, T3 and T4) checked at least every 3 months, or more often as needed to keep them in normal range during pregnancy.
  • Expect that you may need to change the dose of your thyroid medication during and after your pregnancy.

Can low thyroid levels increase a baby’s risk of low IQ?

Babies born to mothers with untreated hypothyroidism during pregnancy are four times more likely to have low IQ or other learning difficulties. However, when the mother’s thyroid levels are within normal range, her children have IQ test scores similar to children born to mothers without thyroid problems.

I worry about taking any medicine during pregnancy. Is it really safe to take my thyroid hormone pill?

It is not only safe, but very important to take your thyroid replacement medication during pregnancy. These medications (Synthroid, Levoxyl, Levothroid, Armour, or Thyrolar) replace the normal hormones you need for a healthy pregnancy. Without enough thyroid hormone, there is a higher risk of miscarriage, high blood pressure, preterm labor, and problems with the baby’s brain development.

Can I take my thyroid medication with my prenatal vitamin, or with food?

Prenatal vitamins, iron supplements, antacids, and certain foods interfere with the body’s absorption of thyroid hormone. When you are pregnant your body must get enough thyroid hormone. Take your thyroid medication on an empty stomach at least one hour before or two hours after meals. Do not take prenatal vitamins or antacids within two hours of your thyroid medication. Be consistent. If you cannot take your thyroid pill without food, it is better to take it every day with food than to miss some days. If you can’t keep your thyroid pill down because of morning sickness, be sure to tell your care provider.

I have heard about the many benefits of breastfeeding. Can I nurse my baby while taking thyroid medication?

Yes, nursing is the healthiest choice for feeding your baby. Mothers continue to take thyroid medication and check their blood thyroid levels while nursing. With the correct dose, thyroid medication will not harm your baby. With a normal amount of thyroid hormone, your body will make plenty of breast milk for your baby.

Will my baby have hypothyroidism too?

All babies are tested for hypothyroidism soon after birth. Hypothyroidism is very rare in infants and children. If thyroid disease is passed on genetically, it usually does not appear until later in life.

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