Thyroid Therapy for Mild Thyroid Deficiency in Pregnancy (TSH)

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Information provided by (Responsible Party):
The George Washington University Biostatistics Center Identifier:
First received: October 12, 2006
Last updated: October 19, 2015
Last verified: October 2015
The purpose of this study is to determine whether treating women, who are diagnosed with a mild imbalance of thyroid hormones during pregnancy, with thyroid hormone replacement affects their children's intellectual development at 5 years of age.

Condition Intervention Phase
Subclinical Hypothyroidism
Drug: Levothyroxine
Drug: Placebo for Levothyroxine
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: A Randomized Trial of Thyroxine Therapy for Subclinical Hypothyroidism or Hypothyroxinemia Diagnosed During Pregnancy

Resource links provided by NLM:

Further study details as provided by The George Washington University Biostatistics Center:

Primary Outcome Measures:
  • Intellectual function of children at 5 years of age, as measured by the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III), in women diagnosed with a) subclinical hypothyroidism or b) hypothyroxinemia during the first half of pregnancy [ Time Frame: 60 months of age ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Developmental delay at 12 and 24 months, using the Bayley Scales for Motor Development Index (MDI) and Psychomotor Development Index (PDI) [ Time Frame: 12 and 24 months of age ] [ Designated as safety issue: No ]
  • Attention deficit at 48 months, using the Connors Rating Scales and the Developmental Neuropsychological Assessment (NEPSY) attention subtests [ Time Frame: 48 months of age ] [ Designated as safety issue: No ]
  • Behavioral problems and social competencies at 36 and 60 months of age, as measured by the Child Behavior Checklist (CBCL) [ Time Frame: 36 and 60 months of age ] [ Designated as safety issue: No ]
  • Fetal growth [ Time Frame: Delivery ] [ Designated as safety issue: No ]
  • Preterm delivery [ Time Frame: Delivery ] [ Designated as safety issue: No ]
  • Preeclampsia [ Time Frame: Duration of pregnancy, Delivery ] [ Designated as safety issue: No ]
  • Abruption [ Time Frame: Duration of pregnancy, delivery ] [ Designated as safety issue: No ]
  • Stillbirth [ Time Frame: Delivery ] [ Designated as safety issue: No ]
  • Development of postpartum thyroid dysfunction [ Time Frame: 12 and 60 months postpartum ] [ Designated as safety issue: No ]

Enrollment: 1203
Study Start Date: October 2006
Study Completion Date: October 2015
Primary Completion Date: August 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Levothyroxine
Drug: Levothyroxine
Coded study drug is thyroxine encapsulated in a gel capsule; matching placebo contains only cellulose. Color of capsule corresponds to mcg dose level (100mcg or 25 mcg). Subjects in subclinical hypothyroidism stratum are started on 1 capsule of 100 mcg per day; subjects in hypothyroxinemia stratum are started on 2 capsules of 25 mcg per day. Thyroxine dosing adjustments for both strata are determined centrally, using an algorithm, based on results of monthly TSH or free-T4 assays. Subjects take study medication until delivery.
Placebo Comparator: Placebo for Levothyroxine
Placebo for Levothyroxine
Drug: Placebo for Levothyroxine

Detailed Description:

Published research reports have stimulated national and international controversy regarding the value of maternal thyroxine therapy given to improve neurodevelopment of the fetus in women with variously defined hypothyroidism. These reports have led to conflicting and confusing recommendations as to whether or not all pregnant women in the U.S. should be screened for subclinical hypothyroidism or hypothyroxinemia.

Pregnant women less than 20 weeks gestation will have a blood test to screen for subclinical hypothyroidism or hypothyroxinemia. If eligible for the trial, patients will receive levothyroxine or placebo until delivery. Blood draws will be done at monthly study visits and the dosage will be adjusted based on test results. The children of these patients will have developmental testing done annually until they are 5 years of age.

Comparison(s): thyroxine supplementation versus placebo given during pregnancy to determine whether therapy is effective in improving intellectual ability at 5 years of age.


Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Subclinical Hypothyroidism as defined by an elevated TSH (≥ 3.00 mU/L) and a free-T4 in the normal range (i.e. 0.86 to 1.90 ng/dL) or Hypothyroxinemia as defined by a TSH in the normal range (0.08 to 2.99 micrometers (mU)/L) and a low free-T4 (<0.86 ng/dL)
  • Singleton Pregnancy
  • Gestational age at randomization between 8 weeks 0 days and 20 weeks 6 days

Exclusion Criteria:

  1. Major fetal anomaly or demise
  2. Planned termination of the pregnancy
  3. History of thyroid cancer or current thyroid disease requiring medication
  4. Diabetes, on medication (insulin, glyburide)
  5. Collagen vascular disease (autoimmune disease), such as lupus, scleroderma and polymyalgia rheumatica, on medication
  6. Receiving anticoagulant therapy
  7. Depression, currently on treatment with tricyclics or selective serotonin reuptake inhibitors (SSRIs)
  8. Other known serious maternal medical complications including:

    1. Chronic hypertension requiring antihypertensive medication (including diuretics)
    2. Epilepsy or other seizure disorder, on medication
    3. Active or chronic liver disease (acute hepatitis, chronic active hepatitis) with persistently abnormal liver enzymes
    4. Cancer (including melanoma but excluding other skin cancers)
    5. Heart disease (tachyrhythmia, class II or greater heart disease or on heart medication). Mitral valve prolapse without arrhythmia is not an exclusion.
    6. Asthma, on oral corticosteroids
  9. Known illicit drug or alcohol abuse during current pregnancy
  10. Delivery at a non-network hospital
  11. Participation in another intervention study that influences maternal and fetal morbidity and mortality, or participation in this trial in a previous pregnancy
  12. Unwilling or unable to commit to 5 year follow-up of the infant
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00388297

United States, Alabama
University of Alabama - Birmingham
Birmingham, Alabama, United States
United States, Illinois
Northwestern University
Chicago, Illinois, United States
United States, Michigan
Wayne State University
Detroit, Michigan, United States
United States, New York
Columbia University
New York, New York, United States
United States, North Carolina
University of North Carolina - Chapel Hill
Chapel Hill, North Carolina, United States
United States, Ohio
Case Western University
Cleveland, Ohio, United States
Ohio State University
Columbus, Ohio, United States
United States, Oregon
Oregon Health & Sciences University
Portland, Oregon, United States
United States, Pennsylvania
University of Pittsburgh Magee Womens Hospital
Pittsburgh, Pennsylvania, United States
United States, Rhode Island
Brown University
Providence, Rhode Island, United States
United States, Texas
University of Texas - Southwest
Dallas, Texas, United States
University of Texas Medical Branch - Galveston
Galveston, Texas, United States
University of Texas-Houston
Houston, Texas, United States
United States, Utah
University of Utah Medical Center
Salt Lake City, Utah, United States
Sponsors and Collaborators
The George Washington University Biostatistics Center
National Heart, Lung, and Blood Institute (NHLBI)
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Principal Investigator: Brian Casey, MD University of Texas Southwestern Medical Center
  More Information

Additional Information:
Responsible Party: The George Washington University Biostatistics Center Identifier: NCT00388297     History of Changes
Other Study ID Numbers: HD36801-TSH  HD21410  HD27869  HD27917  HD27860  HD27915  HD34116  HD34208  HD34136  HD40500  HD40485  HD40544  HD40545  HD40560  HD40512  HD36801 
Study First Received: October 12, 2006
Last Updated: October 19, 2015
Health Authority: United States: Institutional Review Board
United States: Federal Government

Keywords provided by The George Washington University Biostatistics Center:
Subclinical Hypothyroidism
Intellectual Development

Additional relevant MeSH terms:
Endocrine System Diseases
Thyroid Diseases processed this record on May 22, 2016