ATA Thyroid Disease in Preconception, Pregnancy, and Postpartum Guideline Summary

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

Document Overview

Document Title: Thyroid Disease in Preconception, Pregnancy, and Postpartum

Authoring Society: American Thyroid Association

Document Publication Date: May 31, 2026

Page Last Reviewed/Updated: Jun 19, 2026

Document Type: Guideline

Country of Publication: United States

Full Text Freely Available: Yes

Full Text Guideline: journals.sagepub.com/doi/10.1177/10507256261445624

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

Supplemental Implementation Resources

Quick-Reference Guide

Document Scope, Criteria, and Use Cases

Document Objectives: Thyroid disease in pregnancy, preconception, and postpartum is a common and clinically relevant problem. Since the publication of the American Thyroid Association (ATA) guidelines in 2017, substantial new clinical and scientific evidence has become available. The aim of these guidelines is to provide clinicians, patients, researchers, and policymakers with evidence-based recommendations on the care of women with thyroid disease before, during, and after pregnancy. The updated guidelines include recommendations on thyroid function testing, iodine supplementation, thyroid autoimmunity, hypothyroidism, hypothyroxinemia, hyperthyroidism and Graves' disease, thyroid nodules and cancer, and postpartum thyroid dysfunction for women with infertility, pregnant women, and women during postpartum and/or lactation. Recommendations are presented using recommendation tables, additional practical considerations are highlighted in boxes, and background information is provided in the text, tables, and figures per disease entity and chronological subset. These 2026 ATA guidelines provide updated, evidence-based recommendations for the diagnosis and management of thyroid disease in women during preconception, pregnancy, and postpartum. While acknowledging that much of the evidence remains of low-to-moderate quality, these guidelines represent current best practices and consensus among international experts from different fields, offering an optimized framework for individualized patient care.

Scope: Assessment and Screening, Counseling, Diagnosis, Management, Prevention

Keywords: Thyroid Disease, pregnancy

Target Patient Population: Thyroid Disease During Pregnancy and the Postpartum

Inclusion Criteria: Female, Adult

Health Care Settings: Ambulatory

Intended Users: Nurse, Nurse Midwife, Nurse Practitioner, Physician, Physician Assistant

Recommendation Development Processes & Methodology

PICO Questions

How do thyroid function tests change during pregnancy?
What is the normal reference range for serum TSH concentrations in each trimester of pregnancy?
What is the optimal method to assess serum T4 concentration during pregnancy?
What is the impact of severe iodine deficiency on the mother, fetus, and child?
What is the impact of mild to moderate iodine deficiency on the mother, fetus, and child?
What is the iodine status of pregnant and breastfeeding women in the United States?
What is the iodine status of pregnant and breastfeeding women worldwide?
Does iodine supplementation in pregnancy and lactation improve outcomes in severe iodine deficiency?
Does iodine supplementation in pregnancy and lactation improve outcomes in mildly to moderately iodine-deficient women?
What is the recommended daily iodine intake in women planning pregnancy, women who are pregnant, and women who are breastfeeding?
What is the safe upper limit for iodine consumption in pregnant and breastfeeding women?
What is the prevalence of thyroid autoantibodies in pregnant women?
What is the natural history of antithyroid antibodies in pregnant women?
How should euthyroid women who are thyroid antibody (Ab)-positive be monitored during pregnancy?
Should euthyroid women with thyroid autoimmunity be treated with selenium?
Is there an association between thyroid antibodies and sporadic spontaneous pregnancy loss in euthyroid women?
Is there an association between thyroid antibodies and recurrent spontaneous pregnancy loss in euthyroid women?
Does treatment with LT4 or intravenous immunoglobulin therapy decrease the risk for pregnancy loss in euthyroid women with thyroid autoimmunity?
Is there an association between thyroid autoantibody positivity and premature delivery?
Does LT4 treatment of euthyroid women who are thyroid autoantibody positive reduce risk for premature delivery?
Is thyroid autoimmunity in euthyroid pregnant women associated with adverse obstetric or child outcomes other than pregnancy loss and premature birth?
Is overt thyroid dysfunction associated with infertility in women?
Is subclinical hypothyroidism associated with infertility in women?
Is thyroid autoimmunity linked to infertility in women?
Is maternal subclinical hypothyroidism associated with worse ART outcomes?
Does treatment of subclinically hypothyroid women improve ART outcomes?
Is treated maternal hypothyroidism associated with worse ART outcomes compared to healthy controls?
Is maternal antithyroid Ab positivity associated with poorer outcomes following ART?
Does treatment of antithyroid Ab–positive euthyroid women improve ART outcomes?
Does ovarian hyperstimulation alter thyroid function?
What is the definition of hypothyroidism in pregnancy?
How is isolated hypothyroxinemia defined in pregnancy?
What adverse outcomes are associated with overt hypothyroidism during pregnancy?
What adverse outcomes are associated with subclinical hypothyroidism during pregnancy?
What adverse outcomes are associated with isolated hypothyroxinemia in pregnancy?
Should women with overt hypothyroidism be treated in pregnancy?
Should women with subclinical hypothyroidism be treated in pregnancy?
Should women with isolated hypothyroxinemia be treated with LT4 in pregnancy?
What is the optimal method of treating hypothyroidism in pregnant women?
What is the biochemical goal when treating hypothyroidism in pregnant women?
Are there circumstances in which euthyroid women are at risk for hypothyroidism once pregnant?
How should women with hypothyroidism or at risk for hypothyroidism be monitored through pregnancy?
How do treated hypothyroid women (receiving LT4) differ from other patients during pregnancy? What changes can be anticipated in such patients during gestation?
What proportion of treated hypothyroid women (receiving LT4 prenatally) require changes in their LT4 dose during pregnancy?
How should preconception LT4 be adjusted in treated hypothyroid women (receiving LT4) planning pregnancy?
How should LT4 be adjusted postpartum?
What is the outcome and long-term prognosis when maternal hypothyroidism is effectively treated through gestation?
Except for measurement of maternal thyroid function, should additional maternal or fetal testing occur in treated hypothyroid women during pregnancy?
What are the causes of thyrotoxicosis in pregnancy?
What is the appropriate initial evaluation of a suppressed serum TSH concentration during the first trimester of pregnancy?
How can gestational transient thyrotoxicosis be differentiated from Graves' hyperthyroidism in pregnancy?
What is the appropriate management of gestational transient thyrotoxicosis?
How should women with GD seeking future pregnancy be counseled?
What is the management of patients with Graves' hyperthyroidism during pregnancy?
Should antithyroid medication be withdrawn or modified in early pregnancy?
What are the principles of thyroid testing and ATD administration when treating Graves' hyperthyroidism during pregnancy?
What are the indications and timing for thyroidectomy in the management of GD during pregnancy?
How should pregnant patients with GD be prepared for urgent nonthyroid surgery?
What is the value of TRAb measurement in the evaluation of a pregnant woman with Graves' hyperthyroidism?
Under what circumstances should additional fetal ultrasound monitoring for growth, heart rate, and goiter be performed in women with Graves' hyperthyroidism in pregnancy?
When should umbilical blood sampling be considered in women with GD in pregnancy?
How should hyperthyroidism caused by autonomous thyroid nodules be handled in pregnancy?
What are the etiologies of thyrotoxicosis in the postpartum period?
How should Graves' hyperthyroidism be treated in lactating women?
What is the prevalence of thyroid nodules during pregnancy?
What is the prevalence of thyroid cancer in women with thyroid nodules discovered during pregnancy?
What is the optimal diagnostic strategy for thyroid nodules detected during pregnancy?
Does pregnancy impact the prognosis of newly diagnosed thyroid carcinoma?
What are the perioperative risks to mother and fetus of thyroid surgery during pregnancy?
How should cytologically benign thyroid nodules be managed during pregnancy?
What are the TSH goals for pregnant women with previously treated thyroid cancer receiving LT4 therapy?
What is the effect of therapeutic radioactive iodine treatment on subsequent pregnancies?
What type of monitoring should be performed during pregnancy in a patient who has already been treated for DTC prior to pregnancy?
What is the relationship between maternal and fetal thyroid hormone status?
Is maternal thyroid hormone (thyroxine or LT4) transferred to the newborn via breast milk?
Should diagnostic or therapeutic radiopharmaceuticals be administered to breastfeeding or lactating women?
Once the thyrotoxic phase of PPT resolves, how often should TSH be measured to screen for the hypothyroid phase?
How often should thyroid function testing be performed after the hypothyroid phase of PPT resolves?

Number of Source Documents: 621

Literature Search Start Date: Monday, January 1, 1990

Literature Search End Date: Sunday, May 29, 2016

Includes peer/external review process?: Yes

Includes public comment process?: No

Methodologist involvement?: No

Patient involvement?: No

Includes multi-disciplinary group?: Yes

Includes systematic review?: Yes

Grades quality of strength of evidence?: Yes

Grades quality of strength of recommendation?: Yes

Discloses funding source?: Yes

Discloses conflicts of interest?: Yes

Includes benefits/harms analysis with recommendations?: Yes

Identifies study selection process?: Yes

Identifies study selection criteria?: Yes

Identifies methods used to evaluate and analyze the evidence?: Yes

Identifies key questions addressed by the systematic review?: Yes

Identifies search strategy?: No