When Emily Fagiano, of Peterboro, New Hampshire, was eight months pregnant with her second son, she was diagnosed with hyperthyroidism, or an overactive thyroid. But it wasn't her obstetrician who detected the problem -- it was the endocrinologist she regularly sees for the type 1 diabetes she's had since childhood. "My obstetrician mistook my symptoms for the normal side effects of third-trimester pregnancy," says Fagiano, who remembers being chronically warm, unable to sleep, and often anxious or irritable.
Women who are predisposed to thyroid disorders are more likely to see them surface for the first time during pregnancy, says P. Reed Larsen, MD, division chief of endocrinology, diabetes, and hypertension at Brigham and Women's Hospital in Boston. But getting a diagnosis can be difficult, since many of the signs of overactive thyroid (chronic warmth, nervousness, heart palpitations, insomnia) or underactive thyroid (fatigue, weight gain, constipation, hair and skin changes) mirror common symptoms of pregnancy.
Yet it's vital that thyroid dysfunctions be managed in pregnancy. Untreated hyperthyroidism puts a mother at risk for cardiac irregularities and weight loss, and in severe cases, may cause fetal malnutrition or birth defects, says Dr. Larsen. Meanwhile, untreated hypothyroidism (underactive thyroid) raises the danger of miscarriage and may compromise baby's brain development. Fortunately, treatment during pregnancy virtually eliminates these risks.
Since pregnant women are not routinely screened for thyroid disorders, women with suspicious symptoms or risk factors -- particularly a personal or family history of thyroid or autoimmune diseases -- should request testing. (Fagiano has both autoimmune diabetes and a mother with hypothyroidism.) Women are treated easily with either a thyroid hormone replacement or antithyroid pill they need to take daily.