What to "Expect" With a Thyroid Disorder

Pregnant women with thyroid disorders have higher pregnancy complication rates

(RxWiki News) There are several disorders associated with the thyroid gland in the neck. It controls how the body uses energy. When it is under- or overactive, a person may have a thyroid disorder.

A recent study found that women with certain thyroid disorders were at higher risk for complications during pregnancy.

"Attend all prenatal appointments."

The study, led by Tuija Männistö, MD, PhD, of the Epidemiology Branch at the Eunice Kennedy Shriver National Institute for Child Health and Human Development, aimed to find out how pregnancies turned out for women with thyroid disease.

The researchers analyzed the information on 223,512 pregnancies of single children (not twins, triplets, etc.) who were born from 2002 to 2008 in the US.

The researchers were specifically looking for women who had hypertension (high blood pressure) or preeclampsia, diabetes, an early birth (preemie), a cesarean section, an induction for labor or an admission to the intensive care unit.

Preeclampsia is a pregnancy complication in which a woman has high blood pressure and protein in her urine. Only delivering the baby will treat it.

All of the comparisons the researchers made were between women with thyroid disorders and women without thyroid disorders.

Three thyroid disorders are hyperthyroidism, hypothyroidism and iatrogenic hypothyroidism.

Hypothyroidism means a woman's thyroid is underactive. Hyperthyroidism means the thyroid is overactive.

Iatrogenic hypothyroidism is an underactive thyroid resulting from medical treatment, such as radiation treatment or surgery.

The study's results showed that women with hypothyroidism were approximately 47 percent more likely than women without thyroid disorders to have preeclampsia and were more than twice as likely to have preeclampsia associated with high blood pressure from another cause.

Women with hypothyroidism were also about 57 percent more likely than women without thyroid disorders to have gestational diabetes and 34 percent more likely to give birth early.

Women with hypothyroidism were about twice as likely to be admitted to the ICU after giving birth.

They were only slightly more likely (15 percent more likely) to need to be induced instead of going into labor naturally.

Women with hypothyroidism were about 31 percent more likely to get a C-section before labor began and 38 percent more likely to need a C-section after labor began.

Being 30 to 50 percent more likely is not a huge amount. Something that's 30 percent more likely is less than being twice as likely.

Women who had hyperthyroidism were 78 percent more likely to have preeclampsia and more than three times as likely to have preeclampsia associated with high blood pressure from another cause.

Women with hyperthyroidism were about 81 percent more likely (almost twice as likely) to give birth early and were 40 percent more likely to need a labor induction.

Women with hyperthyroidism were more than three times more likely to be admitted to the ICU after giving birth.

Another thyroid disease is called iatrogenic hypothyroidism, which is an underactive thyroid resulting from medical treatment, such as radiation treatment or surgery.

Women with iatrogenic hypothyroidism were almost three times more likely than women without thyroid disorders to have a placental abruption. Placental abruption is a dangerous complication in which the placental lining separates from a woman's uterus.

Women with iatrogenic hypothyroidism were twice as likely as women without a thyroid disorder to have a breech presentation, where the baby is positioned feet first.

Women with iatrogenic hypothyroidism were twice as likely to need a C-section after beginning labor on their own.

The researchers concluded that having a thyroid disease puts women at higher risk for pregnancy, labor and delivery complications.

"Although we lacked information on treatment during pregnancy, these nationwide data suggest either a need for better thyroid disease management during pregnancy or that there may be an intrinsic aspect of thyroid disease that causes poor pregnancy outcomes," the authors wrote.

The study was published May 29 in the Journal of Clinical Endocrinology & Metabolism.

The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health.

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Review Date: 
May 29, 2013