Hypothyroidism and Pregnancy

Thyroid disease is something that you may have suffered from prior to your pregnancy. Hypothyroidism is defined as an underactive thyroid. This can be from surgical removal, disease or a congenital issue with your thyroid.

You may have been diagnosed during some routine blood work or because of symptoms or complications. You may find out before you are pregnant at your preconception health care or in early pregnancy if your practitioner screens.

Screening During Pregnancy

There is no universal screening for hypothyroidism in pregnancy. If you are concerned about your thyroid because of family history, symptoms or other reasons, be sure to ask your practitioner for a simple blood test to screen for your thyroid-stimulating hormone (TSH) levels and your free T4 (thyroxine) levels.

Can It Harm My Pregnancy?

About 2 out of 1,000 pregnancies will be complicated by clinical hypothyroidism and another approximately 2% of pregnancies suffer from subclinical hypothyroidism. The biggest risk is that when a mother has an elevated TSH level, there is an increased risk of your baby have poor intellectual development and a lowered IQ.

Some women with overt hypothyroidism will also suffer from infertility. If this is the case, you may also be at risk for other complications including placental abruption, premature birth, stillbirth, and other complications. Note that after treatment for hypothyroidism, most women are able to conceive. Talk to your practitioner about your specific risks and treatment options.

Though, in general, if your thyroid levels are within normal limits before pregnancy, your risks are greatly reduced. This is why it is important to talk to your practitioner prior to getting pregnant.

How Is It Treated in Pregnancy?

Typically you will need to have your thyroid levels checked every 4-6 weeks during your pregnancy. Many women find that they will need to adjust their replacement thyroxine upwards in pregnancy. Though this is not necessarily true for everyone. Your physician or midwife will increase your dose by 25-50 mcg until you are within normal limits.

Postpartum will be another time to watch your levels because you will most likely need to adjust your medications after you have your baby. This can happen over the course of a few weeks to months and is not necessarily apparent right away.

Will Thyroid Medications Harm My Baby?

Thyroid medications are considered very safe for pregnancy and breastfeeding. Though they may need to be adjusted regularly in pregnancy and postpartum. This may mean having your blood work done more often than when you aren't pregnant.

Hypothyroidism and Labor

You should notice no changes in how you give birth when you have thyroid disease.

Will My Baby Be Hypothyroid?

There is no way to know without testing your baby. There is newborn screening for congenital hypothyroidism in every state. Your baby will be tested within a few days of birth. There will be follow up if the results are inconclusive or if the baby tests positive.