Pregnant women in their first trimester should have their thyroid checked to avoid the risk of serious complications.
A recent study, conducted by Dr. Jubbin Jacob at Christian Medical College and Hospital in India, found that even moderate thyroid dysfunction during the first 20 weeks of pregnancy could greatly increase the risk of serious problems in both mother and baby, like premature labor and low birth weight.
In addition, pregnant women with abnormal thyroid function have double the risk for miscarriage. They also have seven times greater risk of stillbirth.
“There is evidence that untreated symptomatic hypothyroidism can lead to preterm labor, low birth weight and impaired brain development for the baby, and increases the risk for pre-eclampsia or placental abruption for the mother,” said Dr. Fred Seale, an obstetrician and gynecologist at the Ogden Women’s Clinic.
The thyroid is a gland that sits at the front of the lower part of the neck; it produces hormones important in regulating the body’s metabolism.
If the thyroid is low, it is called hypothyroidism. If it’s too high, it’s called hyperthyroidism. The study focused on hypothyroidism.
Early symptoms of a low thyroid include fatigue, constipation, depression, sensitivity to cold temperatures, weight gain, weakness, joint or muscle pain and thin, brittle hair and fingernails. Symptoms of hyperthyroidism include fatigue, weight loss, racing heartbeat and sweating.
However, because many of these symptoms can go along with pregnancy, Seale said it’s important for the tests to be interpreted correctly.
Screening for the thyroid involves taking a thorough history of symptoms as well as a simple blood test to measure levels of thyroid-stimulating-hormone, or TSH.
During the study, researchers recruited and tested 1,000 pregnant women in their first trimester. Normal thyroid function was found in 533 patients; 263 had mild dysfunction. The remaining patients were diagnosed with hypothyroidism and withdrawn from the study for treatment. Followup continued until the completion of pregnancy.
The researchers then compared rates of miscarriage, stillbirth, premature labor and low birth weight. They also analyzed several other complications as well, but these did not differ significantly.
“Our conclusions are that all pregnant women need to be screened for thyroid dysfunction at their first visit,” Jacob said. “This should form the basis for the national societies to make a change in their guidelines.”
Seale said patients in his clinic are routinely screened for abnormal thyroid levels.
“It is surprising how many patients with asymptomatic hypo or hyperthyroidism we identify,” he said. “Screening for thyroid disease in early pregnancy is a reasonable strategy, but is not universally done by all providers.
“If your provider is not doing thyroid screening, it does not mean they are providing substandard care. Guidelines may change in the near future, making stronger recommendations for routine testing.”