How pregnancy, childbirth changes thyroid function
Pregnancy innately changes the ways a body works, but preexisting conditions or genetic predisposition to certain diseases also may factor into those changes.
Thyroid disease, often unrecognized in women, can majorly affect a person’s pregnancy – from fetal side effects to difficulty in breast feeding, said Dr. Ruchi Gaba, associate professor of medicine – endocrinology, diabetes and metabolism.
Thyroid function is already part of the medical tests scheduled for early pregnancy, but Gaba said symptoms can linger after birth even for those who didn’t exhibit thyroid function issues before pregnancy.
“The thyroid hormone is primarily responsible for controlling the body’s metabolism. If underactive, it’s hypothyroidism. If overactive, there’s too much hormone (hyperthyroidism),” Gaba said.
Symptoms for an underactive thyroid include weight gain, feeling tired or sluggish, excessive sleepiness during the day, constipation, cold intolerance, hair and nail changes post-pregnancy or during pregnancy (hair loss) and lower extremity swelling.
An overactive thyroid can cause a person to lose weight, excessive tiredness, heart palpitations and tremors, feeling hot all the time and insomnia. Hyperthyroidism can be caused by Grave’s disease, which is an autoimmune thyroid disease, Gaba said, adding that this is the most common way women develop an overactive thyroid hormone.
For a pregnant person, thyroid fluctuations can cause developmental delays in birth, preeclampsia, preterm birth and in-utero effects on the growing fetus. Gynecologists monitor thyroid function changes throughout pregnancy; if severe enough, the doctor may recommend following up with an endocrinologist for blood work.
Following birth, Gaba said those with a preexisting thyroid issue are at a higher risk of post-partum thyroiditis, a condition that temporarily causes hyperthyroidism followed by hypothyroidism. Usually temporary, there are times when post-partum thyroiditis will result in long-term hypothyroidism.
Autoimmune thyroid dysfunction also may occur because of hormonal changes that happen during pregnancy and childbirth; this is especially true for those with a family history of thyroid function disorders.
Hypothyroidism (underactive thyroid) can lead to less breast milk production because prolactin, a hormone that helps with milk secretion, is affected. However, if a person is on adequate hormone replacement, their milk production should be normal, Gaba said.
Treatment of hypothyroidism typically includes a thyroid hormone replacement pill daily, Gaba said. Most primary care physicians will check a patient’s thyroid function yearly, and it’s important for anyone with a family history of autoimmune thyroid disease to be tested regularly.
“As soon as a woman gets pregnant, part of their first panel will be thyroid function tests,” she said. “Seek preconception counseling and visits with your gynecologist.”
By Julie Garcia
