Objective

Overview

Understanding Thyroid Basics

When Thyroid Testing Is Recommended

Hypothyroidism

Hyperthyroidism

Thyroid Nodules and Thyroid Cancer

Thyroid Dysfunction Postpartum

Design and created by Guideline Central in participation with the American Thyroid Association.

Thyroid Disease in Preconception, Pregnancy, and Postpartum

American Thyroid Association

Publication Date: June 19, 2026

Treatment Options for Graves' Disease Before Pregnancy

Women with Graves' disease who are planning pregnancy have several treatment options to consider, each with different advantages and tradeoffs.
Continuing antithyroid medication during pregnancy:
- Advantages:
  - Easy to take, adjust or stop, and generally inexpensive
  - Usually the fastest way to reach normal thyroid levels, often within 1 to 2 months
  - Very low risk of permanent hypothyroidism.
- Disadvantages:
  - Small increased risk of birth defects: about 3% with propylthiouracil, 5% with methimazole
  - Taking too much can cause an underactive thyroid in the baby
  - Additional ultrasounds during pregnancy are typically needed
  - Thyroid problems can return after delivery if the medication is stopped during pregnancy.
Stopping antithyroid medication upon a positive pregnancy test:
- Advantages:
  - May be an option for women at low risk of the condition returning, generally those who have been on a low, stable dose for more than 6 months.
- Disadvantages:
  - Risk that hyperthyroidism may return either early in pregnancy or after delivery.
Radioactive iodine therapy:
- Advantages:
  - Non-invasive, one-time oral treatment
  - Often shrinks an enlarged thyroid (goiter)
  - Can permanently resolve hyperthyroidism.
- Disadvantages:
  - Pregnancy must be avoided for at least 6 months afterward, since it may increase the risk of fetal and neonatal hyperthyroidism
  - More than one dose is sometimes needed
  - Permanent hypothyroidism is likely
  - Cannot be used in women with moderate to severe thyroid eye disease.
Thyroid surgery (total thyroidectomy):
- Advantages:
  - Definitive treatment that permanently resolves hyperthyroidism
  - Normal thyroid levels usually achievable within 1 to 2 months using thyroid hormone replacement
  - Can relieve symptoms from an enlarged thyroid.
- Disadvantages:
  - Permanent hypothyroidism is guaranteed, requiring lifelong thyroid hormone replacement
  - Surgical risks include temporary vocal cord nerve injury (about 7%) or permanent injury (less than 1%) and a small risk of permanent low calcium levels (up to 6%) from damage to the parathyroid glands
  - Requires a recovery period.

Source Citation

Korevaar, Tim I M et al. “American Thyroid Association 2026 Guidelines for Thyroid Disease in Preconception, Pregnancy, and Postpartum.” Thyroid : official journal of the American Thyroid Association vol. 36,5 (2026): 481-544. doi:10.1177/10507256261445624

Disclaimer

The information in this patient summary should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.

Thyroid Disease in Preconception, Pregnancy, and Postpartum

Objective

Overview

Understanding Thyroid Basics

TSH (Thyroid-Stimulating Hormone)

FT4 (Free Thyroxine)

T3 (Triiodothyronine)

Thyroid Antibodies

Common Thyroid Conditions

Understanding Thyroid Test Results

Before Pregnancy & During Fertility Treatment

During Pregnancy

Iodine Nutrition

When Thyroid Testing Is Recommended

Before Pregnancy & During Fertility Treatment

During Pregnancy

Postpartum

Hypothyroidism

What Is Hypothyroidism?

Levothyroxine Targets and Testing Schedule

Before Pregnancy & During Fertility Treatment

Overt Hypothyroidism

Subclinical Hypothyroidism

Thyroid Autoimmunity

During Pregnancy

Overt Hypothyroidism During Pregnancy

Subclinical Hypothyroidism During Pregnancy

Thyroid Autoimmunity During Pregnancy

Isolated Hypothyroxinemia During Pregnancy

Postpartum (Newborn Screening)

Hyperthyroidism

What Is Hyperthyroidism?

Before Pregnancy & During Fertility Treatment

Graves' Disease Preconception

Treatment Options for Graves' Disease Before Pregnancy

During Pregnancy

Evaluating Hyperthyroidism During Pregnancy

Subclinical and Overt Hyperthyroidism During Pregnancy

Monitoring Graves' Disease in Pregnancy

ATD Treatment of Graves' Disease During Pregnancy

Thyroid Surgery for Graves' Disease in Pregnancy

Fetal Hyperthyroidism

Postpartum (Newborn Screening)

Thyroid Nodules and Thyroid Cancer

Autonomous Thyroid Nodules

Preconception

During Pregnancy

Differentiated Thyroid Cancer

Preconception

During Pregnancy

Thyroid Cancer in Lactation

Medullary and Advanced Thyroid Cancers

Medullary Thyroid Cancer and Pregnancy

Advanced Thyroid Cancers in Pregnancy

Thyroid Dysfunction Postpartum

Postpartum Thyroiditis

Other Postpartum Thyroid Dysfunction

Managing Postpartum Hyperthyroidism Not Related to PPT

Postpartum Follow-Up of Levothyroxine Started During Pregnancy

Source Citation

Disclaimer