Your thyroid is the gland that makes hormones that control your metabolism, helping to regulate body weight, heart rate and a host of other factors. During pregnancy, having an underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism) may lead to miscarriage, premature birth and pre-eclampsia — and in the case of hypothyroidism, impaired intelligence in the child.
Thyroid porblems can easily go undetected so doctors are debating whether a universal thyroid function test should be standard procedure for a pregnant woman.
Currently, the American Thyroid Association does not suggest a universal thyroid function test for pregnant women however they are holding a symposium this Thursday and Friday in Washington to discuss the most recent research.
According to the New York Times, symptoms of a wayward thyroid can be subtle, and pregnancy can mask them. Fatigue, weight gain and dry skin — all typical in pregnant women — can also result from hypothyroidism, said Dr. Alex Stagnaro-Green, an endocrinologist at Touro University College of Medicine in Hackensack, N.J.
The opposite condition, hyperthyroidism, affects roughly 2 in 1,000 pregnancies. But again, its symptoms — poor sleep, weight loss and nervousness after childbirth — could result from other postpartum conditions.
Hypothyroidism, which usually arises from underlying autoimmune disease, is the more frequent and worrisome concern. As many as 10 to 20 percent of reproductive-age women test positive for antibodies that attack the thyroid gland and may eventually destroy it. Their risk of miscarriage is doubled.
Three to five out of 1,000 women of childbearing age suffer from overt hypothyroidism, in which thyroid hormone, or T4, is low and T.S.H. is abnormally high. But the most common thyroid dysfunction is subclinical hypothyroidism, in which T4 is normal but T.S.H. is slightly elevated. That condition affects 2 to 3 percent of women but often goes undiagnosed when it causes no obvious symptoms.
Hypothyroidism may harm fetal brain development. Ten years ago, researchers in Maine analyzed blood samples from 25,216 pregnant women and identified 62 with hypothyroidism. Their children, by then 7 to 9 years old, were given intelligence tests. Nineteen percent of the children born to women with an untreated underactive thyroid had an I.Q. of 85 or lower, compared with 5 percent of those whose mothers had a healthy thyroid. “At about 85 or below, that’s where you begin to have trouble in school and in life in general,” said Dr. James E. Haddow, a pediatrician at Brown University who was an author of the study. But if mothers had their hypothyroidism treated, their children’s intelligence was not impaired.