Pregnancy's Effect on Other Health Conditions

How Pregnancy Affects Thyroid Disorders

Having a baby can do quite a number on the thyroid, a butterfly-shaped gland in your neck that releases hormones regulating nearly every process in the body. There are three ways pregnancy can affect your thyroid:

Hypothyroidism (Low Levels of Thyroid Hormone)

Hypothyroidism affects nearly one out of 50 pregnant women, according to the American Association of Clinical Endocrinologists. Some enter into pregnancy with the disorder; others develop the condition during pregnancy. Symptoms -- like fatigue, forgetfulness, weight gain, and constipation -- often overlap with those of pregnancy, so the condition can go undiagnosed. Plus, some women have no signs at all.

If you suspect you have hypothyroidism, ask your doctor for a simple blood test. Pregnancy complications such as premature birth and miscarriage have been associated with the condition, says Jeffrey R. Garber, MD, author of The Harvard Medical School Guide to Overcoming Thyroid Problems (McGraw-Hill), so you'll want to get treatment.

Hyperthyroidism (High Levels of Thyroid Hormone)

Hyperthyroidism is far less common, affecting about one in 500 pregnancies, but harder to treat because the drugs prescribed for it can harm a baby. It may also be confused with hyperemesis gravidarum, a severe form of morning sickness, says Dr. Garber. Symptoms include a fast heart rate, nervousness, weight loss, intolerance to heat, and bulging eyes.

Postpartum Thyroiditis

Postpartum thyroiditis affects up to 10 percent of new moms, says the American Thyroid Association. Signs include anxiety, insomnia, fast heart rate, weight loss, and fatigue. Many of these are also the hallmarks of having just given birth, so it's not uncommon to confuse postpartum thyroiditis with postpartum depression. "Sometimes a goiter (enlarged thyroid) is a tip-off, and ob-gyns are attuned to that at the six-week postpartum visit," Dr. Garber says. But your doctor might not pick up on a thyroid issue that has less recognizable symptoms.

Lorie Parch is a freelance writer based in Scottsdale, Arizona.

Originally published in American Baby magazine, June 2007.

All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.