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Completed

NCT Number: NCT00388297

Thyroid Therapy for Mild Thyroid Deficiency in Pregnancy

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.

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Key information

Sex eligibility

Female

Study type

Interventional

Phase

Phase 3

Primary location

University of Alabama - Birmingham, Birmingham, Alabama, United States

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About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

  • Major fetal anomaly or demise
  • Planned termination of the pregnancy
  • History of thyroid cancer or current thyroid disease requiring medication
  • Diabetes, on medication (insulin, glyburide)
  • Collagen vascular disease (autoimmune disease), such as lupus, scleroderma and polymyalgia rheumatica, on medication
  • Receiving anticoagulant therapy
  • Depression, currently on treatment with tricyclics or selective serotonin reuptake inhibitors (SSRIs)
  • Other known serious maternal medical complications including:
  • Chronic hypertension requiring antihypertensive medication (including diuretics)
  • Epilepsy or other seizure disorder, on medication
  • Active or chronic liver disease (acute hepatitis, chronic active hepatitis) with persistently abnormal liver enzymes
  • Cancer (including melanoma but excluding other skin cancers)
  • Heart disease (tachyrhythmia, class II or greater heart disease or on heart medication). Mitral valve prolapse without arrhythmia is not an exclusion.
  • Asthma, on oral corticosteroids
  • Known illicit drug or alcohol abuse during current pregnancy
  • Delivery at a non-network hospital
  • Participation in another intervention study that influences maternal and fetal morbidity and mortality, or participation in this trial in a previous pregnancy
  • Unwilling or unable to commit to 5 year follow-up of the infant

Treatment and study plan

Levothyroxine

Drug

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 for Levothyroxine

Drug

Primary outcomes

  1. Intellectual Function of Children at 5 Years of Age in Women Diagnosed With a) Subclinical Hypothyroidism or b) Hypothyroxinemia During the First Half of Pregnancy, or Death.

    Time frame: 60 months of age

    The primary outcome was death or IQ score at 5 years of age (or at 3 years of age if the 5-year examination was missing). The full-scale IQ was assessed with the use of the Wechsler Preschool and Primary Scale of Intelligence III (WPPSI-III) at 5 years of age or the overall (general conceptual ability) score from the Differential Ability Scales-II at 3 years of age if the WPPSI-III score was not available. Results are expressed as an age-standardized score, with an expected population mean of 100 and a standard deviation of 15. Death before 3 years of age was assigned a score of 0 (lowest possible rank) and was included in the estimation of the median.

    For Quotient and Composite score:

    below 70 is Extremely Low, 70-79 is Borderline, 80-89 is Low Average, 90-109 is Average, 110-119 is High Average, 120-129 is Superior, 130+

Secondary outcomes

  1. Week of Gestation at Delivery

    Time frame: Delivery

    Gestational age at delivery and preterm birth < 37 weeks' gestation or < 34 weeks' gestation

  2. Number of Participants With Preterm Delivery

    Time frame: Delivery

    Preterm delivery at less than 37 weeks or less than 34 weeks gestation

  3. Selected Cognitive Abilities From the Subscales of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III)

    Time frame: 60 months

    Standardized full-scale IQ scores from the Wechsler Preschool and Primary Scale of Intelligence III (WPPSI-III) at 5 years of age. Quotient and Composite scores have a mean of 100 and a standard deviation of 15. Subtest scaled scores have a mean of 10 and a standard deviation of 3.

    For Quotient and Composite score:

    below 70 is Extremely Low, 70-79 is Borderline, 80-89 is Low Average, 90-109 is Average, 110-119 is High Average, 120-129 is Superior, 130+ is Very Superior.

  4. Cognitive and Achievement Levels From the Differential Ability Scales (DAS II)

    Time frame: 36 months

    Overall general conceptual ability score as measured by the DAS-II at 36 months of age.

    GCA General Conceptual Ability Classification ≥ 130 Very high 120-129 High 110-119 Above average 90-109 Average 80-89 Below average 70-79 Low

    ≤ 69 Very low

  5. Cognitive and Achievement Levels From Two DAS-II Subtests (Recall of Digits Forward and Recognition of Pictures)

    Time frame: 48 months of age

    Cognitive and achievement levels from two DAS-II subtests (Recall of Digits Forward and Recognition of Pictures)

    GCA General Conceptual Ability Classification ≥ 130 Very high 120-129 High 110-119 Above average 90-109 Average 80-89 Below average 70-79 Low

    ≤ 69 Very low

  6. Cognitive, Motor and Language Scale Scores From the Bayley Certified Scales of Infant Development III Edition

    Time frame: 12 and 24 months of age

    Composite scores are derived for cognitive, language, and motor development and scaled to a metric, with a mean of 100, standard deviation of 15, and range of 40 to 160. Results can also be expressed as percentile ranks relative to the standardization sample, with a mean and median of 50 and range from 1 to 99

  7. 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

    Behavioral problems and social competencies at 36 and 60 months of age, as measured by the Child Behavior Checklist (CBCL). The CBCL is filled out by the caregiver. Each of the 100 questions indicates a behavior for which the caregiver scores as Not True (0), Sometimes True (1), or Often True (2). The scores for all the questions are then summed and evaluated against the normative data/T-scores. A Tscore of less than 60 is considered to be in the normal range. A T score of 60-63 is a borderline, and a T score of more than 63 is in the clinical range. Lower scores represent better outcomes.

  8. Attention Deficit Hyperactivity Disorder (ADHD) Index Score From the Connors' Rating Scales (Parent-S) - Revised

    Time frame: 48 months of age

    The Conners' Rating Scales-Revised were used to assess attention deficit-hyperactivity disorder (ADHD). A T score of 45 to 55 is considered to be typical or average; a T score of 44 or less is not a concern, a T score of 56 to 60 is considered to be a borderline score, and a T score of 61 or higher indicates a possible or clinically significant problem.

  9. Participants With Placental Abruption

    Time frame: Duration of pregnancy, delivery

    Clinically significant placental abruption will be determined by centralized (blinded) chart review

  10. Participants With Gestational Hypertension

    Time frame: During pregnancy and until delivery

    Gestational hypertension defined as patient having a diastolic ≥ 90 during pregnancy without proteinuria

  11. Participants With Preeclampsia

    Time frame: Duration of pregnancy, Delivery

    Preeclampsia defined as patient having a diastolic ≥ 90 during pregnancy with at least 1 + proteinuria. Preeclampsia will also include HELLP syndrome or eclampsia.

  12. Gestational Diabetes Mellitus

    Time frame: During pregnancy until delivery

    A patient is considered to have gestational diabetes if clinically diagnosed with class A1 or A2

  13. Participants With Composite Neonatal Outcome

    Time frame: Within 72 hours of delivery.

    The composite neonatal outcome was defined as periventricular leukomalacia, intraventricular hemorrhage of grade III or IV, necrotizing enterocolitis (stage ≥II), severe retinopathy of prematurity (stage ≥III), the severe respiratory distress syndrome, bronchopulmonary dysplasia, neonatal death, stillbirth, or serious infectious complication.

  14. Participants Who Experienced a Stillbirth or Miscarriage

    Time frame: Delivery

    Stillbirth or miscarriage.

  15. Number of Neonatal Deaths

    Time frame: Through 72 hours post delivery

    Fetal and neonatal death

  16. Number of Infants With Apgar Score 4 at 1 Minute and < 7 at 5 Minutes

    Time frame: 1 minute and 5 minutes post delivery

    Apgar score < 4 at 1 minute and < 7 at 5 minutes

  17. Number of Infants Admitted to NICU

    Time frame: Delivery

    Admission to NICU

  18. Infants With Birth Weight < 10th Percentile (Gestational Age z Score)

    Time frame: Delivery

    Birth weight < 10th percentile (gestational age z score)

  19. Neonatal Head Circumference (Centimeters)

    Time frame: Within 24 hours of birth

    Neonatal head circumference measured within 24 hours of birth. This measurement is included based on a report showing that maternal treatment with thyroxine for overt hypothyroidism was associated with reduced head circumference in the newborn infant

  20. Number of Infants With Respiratory Distress Syndrome

    Time frame: Delivery and greater than or equal to 24 hours

    Respiratory distress syndrome (RDS) will be defined based on a clinical diagnosis of RDS Type I and oxygen therapy (FiO2 ≥ 0.40) for greater than or equal to 24 hours. For infants dying before 24 hours of age, a clinical diagnosis of RDS Type I and oxygen therapy (FiO2 ≥ 0.40) are sufficient.

  21. Number of Infants With Retinopathy or Prematurity

    Time frame: Through 72 hours of birth

    This diagnosis will be reached when an ophthalmologic examination of the retina has been performed and ROP is diagnosed at Stage I (demarcation line in the retina) or greater

  22. Number of Infants With Necrotizing Enterocolitis

    Time frame: Delivery within 2 weeks of birth

    Necrotizing enterocolitis (NEC) is defined by the following: the unequivocal presence of intramural air on abdominal x-ray, perforation seen on abdominal x-ray, clinical evidence as suggested by erythema and induration of the abdominal wall, or intra-abdominal abscess formation, or stricture formation observed at surgery or autopsy following an episode of suspected NEC. The condition is classified based on the Bell staging system

  23. Number of Infants With Bronchopulmonary Dysplasia

    Time frame: Through 72 hours post delivery

    Bronchopulmonary dysplasia (BPD) is defined as the need for supplemental oxygen at 36 weeks corrected age, for babies born <34 weeks by project gestational age only

  24. Number of Infants With Respiratory Therapy Greater Than or Equal to 1 Day

    Time frame: 72 hours post delivery

    oxygen therapy (FiO2 ≥ 0.40) for greater than or equal to 24 hours

  25. Number of Days in the Hospital Nursery

    Time frame: Through hospital discharge

    Median number of days in the hospital nursery

Sponsors and collaborators

Lead sponsor

The George Washington University Biostatistics Center

Other

Collaborators

  • Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
  • National Institute of Neurological Disorders and Stroke (NINDS)

Registry information

Official study title

A Randomized Trial of Thyroxine Therapy for Subclinical Hypothyroidism or Hypothyroxinemia Diagnosed During Pregnancy

Acronym: TSH

Important dates

Study start
2006
Primary completion
2015
Study completion
2015
First posted
Oct 16, 2006
Registry last updated
Feb 21, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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