Maternal Hypothyroidism & Newborn Health: Risks & Effects

The thyroid gland controls the metabolic rate and regulates growth and development. Hypothyroidism is the underproduction of thyroid hormones. If left untreated, maternal hypothyroidism can have profound effects on a newborn.

Pregnancy Risk

• Severe maternal hypothyroidism can cause preeclampsia (toxemia), placental abnormalities and abruptio placentae, all of which pose significant risks for the fetus. According to Olds' Maternal-Newborn Nursing, there is a 50 percent increased risk of spontaneous miscarriage.

Lower IQ

• One-third of the infants of untreated mothers showed significantly lower IQ scores. This is nearly twice the rate of babies born to mothers with normal thyroid levels.

Motor and Gait

• Maternal hypothyroidism during pregnancy has been shown to increase the risk of delayed psychomotor development in infants.

Combined Maternal and Fetal Hypothyroidism

• The effects of combined maternal and fetal hypothyroidism are more severe than maternal hypothyroidism alone. Such cases can lead to severe cretinism, a congenital condition of stunted physical development and extremely low IQ (around 29) caused by severe thyroid deficiency.

Treatment

• Treatment during pregnancy consists of replacement of thyroid hormone with synthetic levothyroxine. If possible, a woman should be treated for hypothyroidism before becoming pregnant. Adequate treatment during pregnancy can prevent the negative effects of maternal hypothyroidism.