Thyroid Disease and Pregnancy: Risks, Diagnosis, Symptoms & Treatment

Thyroid disease is an issue that can affect the health of mothers and their children both during and after pregnancy if contracted.

Thousands of expecting mothers will be diagnosed with a disorder of the thyroid and will quickly learn that it’s a condition with the possibility of causing severe complications during pregnancy, as well as afterward if not monitored properly.

However, under the care of a doctor, these common diseases can be controlled and the pregnancy can thrive without any trouble.

Thyroid Disease Overview

The thyroid is an endocrine organ located on the front of your neck that releases hormones which regulate your metabolism, weight, body temperature, and nervous system. Two diseases exist that are related to this organ: hyperthyroidism and hypothyroidism.


Hyperthyroidism is the overproduction of the thyroid hormones while hypothyroidism is the underproduction of the thyroid hormones. If these diseases are diagnosed before pregnancy, the mother’s blood levels of these hormones will need to be monitored on a regular basis.

Maternal thyroid disorders can also occur during pregnancy due to the increased demand for thyroid hormones, which can make a healthy thyroid malfunction. Hyperthyroidism during pregnancy is typically a result of the disorder known as Grave’s disease.

thyroid system

This disease occurs when the body starts making an antibody called thyroid-stimulating immunoglobulin that leads to the overproduction of the thyroid hormone. Hyperthyroidism affects one out of every 500 pregnancies [1].

The overproduction of thyroid hormones is most likely to occur during the first trimester of pregnancy.

Maternal hypothyroidism is usually caused by Hashimoto’s thyroiditis in which the body attacks the thyroid gland cells leading to a deficiency of thyroid hormones.

It occurs in one out of every 1,000 pregnancies or 2-3% of expectant mothers [2].

It’s extremely important to recognize and treat maternal thyroid diseases because if left untreated, they can impair full and normal development of the fetus, leading at times to preterm delivery or miscarriage.

Those at Risk

Some women may be more susceptible to being diagnosed with thyroid disease during pregnancy [3]. If you identify with one or more of the following statements, you should talk to your doctor about your concern and make sure you’re being monitored on a regular basis throughout your pregnancy.

  • Women with a family history of thyroid disease.

  • Women with a goiter

  • Women with any of the symptoms associated with hyperthyroidism or hypothyroidism.

  • Women with Type 1 Diabetes.

  • Women with a history of miscarriage or preterm delivery.

  • Women with infertility issues.

  • Women with morbid obesity or a body mass index greater than 40kg.

  • Women over the age of 30.


Hyperthyroidism when uncontrolled during pregnancy can lead to preeclampsia, congestive heart failure, premature birth, and miscarriage [1]. Hypothyroidism can lead to preeclampsia, anemia, low birth weight, miscarriage, and stillbirth.

It can also affect the baby’s growth and brain development due to the importance of thyroid hormones in fetal nervous system development [4].


Symptoms of thyroid disease differ according to the disease.

Hyperthyroidism Symptoms:

  • Irregular heartbeat
  • Trouble sleeping
  • Severe vomiting
  • Tremors

Hypothyroidism Symptoms:

  • Muscle cramps
  • Cold sensitivity
  • Constipation
  • Extreme fatigue
  • Memory problems


Either disease can be diagnosed after a physical exam and blood tests that measure the levels of thyroid-stimulating hormone (TSH) and thyroid hormones T3 and T4. These tests usually follow a careful review of existing symptoms.


Fortunately, treatment of thyroid disease is fairly simple and effective. If the mother has hyperthyroidism, treatment may not be necessary unless the disease is severe.

In those cases, this condition can be treated with antithyroid medications which help by limiting the thyroid hormone production.

Hypothyroidism is treated with the synthetic thyroid hormone called thyroxine.

If the condition was present before pregnancy, the mother’s dosage will likely need to be increased. Thyroid levels should be checked every six to eight weeks.

Postpartum Thyroid Disorders

Rarely, a new mother can develop Postpartum Thyroid Dysfunction (PPTD) during the twelve months following delivery. This condition has symptoms that mimic Hashimoto’s disease and occurs in 5-9% of women.

Permanent hypothyroidism results in 30% of those women and will require long-term treatment to maintain healthy hormone levels.


  1. Hyperthyroidism in pregnancy.ncbi [Link]
  2. Prevalence of hypothyroidism in pregnancy: An epidemiological study from 11 cities in 9 states of India.ncbi [Link]
  4. Pregnancy and Thyroid Disease [Link]
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