What Expectant Moms Need to Know
Whether a pregnant woman finds out she has thyroid cancer or a thyroid cancer survivor hopes to become pregnant, a cancer diagnosis can add to the existing concerns that come with having a child. Crafting a treatment plan or an approach to pregnancy that will keep a mother and her baby safe starts with understanding the necessary precautions. For families and medical teams, information and attentiveness can ease the journey ahead.
For Patients with a New Diagnosis
Receiving a diagnosis of thyroid cancer may be unsettling, especially for women diagnosed while pregnant. Fortunately, pregnancy does not impact the long-term outcomes of thyroid cancer, and the vast majority face Stage 1 cancer. This kind of thyroid cancer rarely affects life expectancy and does not affect the health of the baby.
Is surgery necessary?
If a woman receives a thyroid cancer diagnosis, she may eventually need surgery to remove her thyroid, but the timing of the procedure may vary. The decision to have surgery depends on many factors. Some studies show no difference in outcome for those who have surgery during pregnancy as compared with those who wait.
Is it safe to have surgery during pregnancy?
The nature of the cancer determines whether a patient will need surgery. Since most thyroid cancers grow slowly, a patient will usually have to wait until after delivery to remove the thyroid. But if the cancer grows rapidly, or has spread outside of the thyroid to lymph nodes in the neck, then a patient may undergo surgery while pregnant. When necessary, the best time for surgery during pregnancy is during the second trimester.
A surgeon can remove the thyroid with safe outcomes during the first and third trimesters, but that time frame is not ideal. A patient’s care team will recommend it only to treat very aggressive disease. If surgery is performed, the risks tend to be minimal, but it should be performed at a center with extensive surgical and obstetric expertise. After having the thyroid removed, the doctor will prescribe a slightly higher amount of thyroid hormone to replace the body’s natural production.
Is radioactive iodine therapy necessary?
Radioactive iodine (RAI) therapy harnesses the unique features of remaining thyroid cells to target them for treatment. Although administered through a painless pill, it may cause side effects such as nausea and dry mouth. It requires isolation to avoid exposing others to the radioactivity of the medicine. Only after surgery and careful examination of the removed tissue can a patient decide about RAI therapy. It is not safe to undergo RAI treatment while pregnant, so even pregnant women who undergo surgery will not receive RAI before delivery. Mothers cannot nurse after receiving RAI.
For Those with a Previous Diagnosis
The highest incidence of thyroid cancer among women occurs between 25 and 45 years of age. Many women receive a diagnosis and get treated for thyroid cancer before starting families. If a woman had thyroid cancer in the past and would like to have children, they should consider a few key factors.
Is it safe to get pregnant after radioactive iodine therapy?
A higher miscarriage rate is associated with patients who become pregnant within the first 6 months following radioactive iodine therapy. So patients must wait until it is safe. After 6 months, however, risk of congenital malformations for babies of mothers who had RAI will not increase.
Women who had RAI should consult their endocrinologists before getting pregnant. The doctor will discuss their history of thyroid cancer and check for recurrent disease. If the doctor finds evidence of disease, they will likely recommend further evaluation and therapy prior to pregnancy. Fortunately, many women remain cancer-free after initial treatment and can become pregnant without delay.
What happens during pregnancy?
Depending on the risk of recurrence for an individual woman, the doctor may recommend blood tests during pregnancy to monitor for thyroid cancer. Thyroglobulin is the biomarker for thyroid cancer, which the patient’s care team will observe closely. Its baseline level is detectable prior to surgery.
Studies show that even in the absence of thyroid cancer, thyroglobulin rises during pregnancy and decreases to baseline after delivery. So a patient can consider some changes normal. In addition to blood tests, the doctor may also ask for an ultrasound of the neck to check the surrounding lymph nodes.
What about women who had a thyroidectomy?
After undergoing thyroidectomy, or removal of the thyroid, thyroid hormone is maintained with a daily pill of synthetic hormone. Women who become pregnant will need an increased dose of synthetic thyroid hormone, beginning as early as 6 weeks into pregnancy. If expectant mothers take prenatal vitamins or iron or calcium supplements, they should take the vitamins 4–5 hours before their thyroid medication to maximize effectiveness. After delivery, mothers can return to their normal dose of thyroid hormone.
