Thyroid & Pregnancy
Thyroid disease is a group of conditions that affect the thyroid gland, a small, butterfly-shaped gland in the front of your neck (NIH, 2017). This gland makes hormones that control how your body uses energy, which means they impact almost every organ in your body, including how your heart beats (NIH, 2017).
Sometimes the thyroid gland makes too much or too little of its hormones (NIH, 2017). When it makes too much, it's called hyperthyroidism, and it can cause your body to speed up (NIH, 2017). 'Hyper' means the thyroid is overactive (NIH, 2017). When it makes too little, it's called hypothyroidism, and it can cause your body to slow down (NIH, 2017). "Hypo" means the thyroid is underactive (NIH, 2017). Pregnancy naturally puts a lot of physical stress on the mother and the baby (Sahay, et al., 2012). However, if the mother also has an endocrine disorder like hypothyroidism, the risks to both her and the baby can increase significantly (Sahay, et al., 2012). Since hypothyroidism is common in pregnancy and can be easily treated, early detection and early treatment could greatly reduce the risk of complications for both the mother and the baby (Sahay, et al., 2012).
Risks of Hypothyroidism to the mother and the baby
Suppose hypothyroidism is untreated or not properly managed. In that case, it can lead to an increased risk of miscarriage and other complications such as maternal anemia, muscle pain and weakness (myopathy), heart failure, pre-eclampsia, placental issues, and heavy bleeding after childbirth (postpartum hemorrhage) (ATA, 2019). These problems are more common in women with severe hypothyroidism (ATA, 2019). Women with mild hypothyroidism might not have any symptoms, or they might mistake their symptoms for normal pregnancy effects (ATA, 2019).
If severe hypothyroidism in a mother goes untreated, it can arm the baby's brain development (ATA, 2019). Recent research also suggests that even mild, untreated hypothyroidism during pregnancy might cause subtle brain development issues in children (ATA, 2019). The American Thyroid Association (ATA) (2019) recommends testing a woman's Thyroid Stimulating Hormone (TSH) levels as soon as the pregnancy is confirmed if she is at a high risk for thyroid disease. This includes women who have previously been treated for thyroid issues, have a family history of hypothyroidism, have a personal history of autoimmune diseases, or goiter (ATA, 2019). Symptoms (NIH, 2017)
The symptoms of an underactive thyroid in pregnant women are often similar to those experienced by others with hypothyroidism. These symptoms include:
Extreme fatigue
Difficulty tolerating cold
Muscle cramps
Severe constipation
Memory or concentration issues
Preparation for a successful pregnancy with Hypothyroidism (Shomon, et al., 2022)
When you have decided to become a parent, ensuring a healthy pregnancy and baby becomes your top priority! If you are being treated for hypothyroidism and planning to have a baby, there are important steps you should take before trying to conceive (Shomon, et al., 2022). These steps can be crucial for a healthy pregnancy while managing hypothyroidism:
Experts recommend beginning your planning at least 6 months before trying to conceive, if possible. This period allows you to test for and address any nutrient deficiencies, ensure your thyroid levels are optimal for fertility, and work with your doctor to create a thyroid management plan (Shomon, et al., 2022).
According to guidelines from the American Thyroid Association (ATA), your doctor should adjust your thyroid hormone replacement medication to keep your thyroid stimulating hormone (TSH) level below 2.5 mlU/L before you conceive. If your TSH levels are higher, your doctor will likely increase your thyroid hormone dosage and re-check your levels until they reach 2.5 or lower (Shomon, et al., 2022).
Consider testing for iodine deficiency iodine deficiency before you conceive, as iodine is essential for thyroid hormone production. If you are low in iodine, your doctor can recommend can appropriate supplement, typically using an iodine/ iodide combination with like Iodoral or Lugol's solution (Shomon, et al., 2022).
Folic acid is crucial before and during pregnancy to help prevent neural tube defects in your baby. Before pregnancy, you can undergo genetic testing to check for the methylenetetrahydrofolate reductase (MTHFR) gene mutation. If you test positive, experts recommend taking a specific form of folic acid called methylfolate, which is better absorbed by those with mutation and helps prevent neural tube defects (Shomon, et al., 2022).
In women without thyroid conditions, the thyroid gland enlarges and increases hormone production by up to 50 percent soon after conception. This increase is vital for your developing baby, whose thyroid doesn’t start producing hormones until the second trimester (Shomon, et al., 2022).
If you have hypothyroidism, it’s important to confirm your pregnancy as early as possible so you can adjust your thyroid medication dosage right away. Early confirmation can help reduce the risk of miscarriage due to thyroid issues or developmental problems in your baby. Don’t wait for a missed period—start testing for pregnancy soon after trying to conceive. Some home pregnancy tests can detect pregnancy as early as seven days after conception (Shomon, et al., 2022).
Consider preconception planning with your healthcare provider to have a plan ready for increasing your thyroid medication dosage once you confirm pregnancy. In some cases, your provider might recommend increasing your dose by up to 50 percent immediately after a positive pregnancy test. Having a plan in place ensures your thyroid levels stay within the optimal range during early pregnancy (Shomon, et al., 2022).
Conclusion
Managing hypothyroidism is crucial for a healthy pregnancy and the well-being of both mother and baby. With proper planning, early detection, and effective treatment, the risks associated with hypothyroidism can be significantly minimized. By following expert guidelines, including optimizing thyroid hormone levels, addressing nutrient deficiencies, and preparing a personalized thyroid management plan with your healthcare provider, you can enhance your chances of a successful pregnancy. Remember that early action—both in planning and in confirming pregnancy—can make a profound difference in outcomes, helping to ensure a healthy and happy start for both you and your baby.
References
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2017). Thyroid Disease & Pregnancy. NIH. https://www.niddk.nih.gov/health-information/endocrine-diseases/pregnancy-thyroid-disease
Sahay, R. K., and Nagesh, V.S. (2012). Hypothyroidism in Pregnancy. Indian J Endocrinol Metab, 16(3), 364-370. doi: 10.4103/2230-8210.95667
American Thyroid Association. (2019). Hypothyroidism in Pregnancy. www.thyroid.org/wp-content/uploads/patients/brochures/hypothyroidism_pregnancy_brochure.pdf
Shomon, M., and Langdon, K. (2022). How To Prepare For Pregnancy With Hypothyroidism. Paloma. https://www.palomahealth.com/learn/prepare-pregnancy-hypothyroidism
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