The Effect of Thyroid Hormone Levels in Pregnant Women on the Intelligence Quotient (IQ) of Their Children
Public ClinicalTrials.gov record NCT00147433. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Are IQs Low in Offspring of Euthyroid Women With Low T4?
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This study is designed to test the hypothesis that the level of the thyroid hormone thyroxine (specifically, free thyroxine, FT4) circulating in the blood of pregnant women is the key thyroid-related factor to influence early fetal brain development. The investigators will recruit 5000 pregnant women with clinically normal thyroid function (normal thyroid stimulating hormone levels) in the second trimester. After the baby has been born, the investigators will measure FT4 in the second trimester maternal blood sample to identify 100 cases (very low FT4 levels) and 100 matched controls (normal FT4 levels). The children of cases and controls will undergo neurodevelopmental testing at 2 years of age to determine whether IQ differs according to maternal FT4 levels during pregnancy. The potential impact of the study is that if such an effect is found, it might be possible to avoid these adverse developmental consequences in children by designing and testing strategies to identify and treat high risk women.
Study identification
- NCT ID
- NCT00147433
- Recruitment status
- Not listed
- Study type
- Observational
- Phase
- Not listed
- Lead sponsor
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- NIH
- Enrollment
- 5,000 participants
Conditions and interventions
Interventions
Not listed
Eligibility (public fields only)
- Age range
- 0 Years and older
- Sex
- Female
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jan 31, 2004
- Primary completion
- Not listed
- Completion
- Oct 31, 2008
- Last update posted
- Mar 30, 2006
2004 – 2008
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Foundation for Blood Research | Scarborough | Maine | 04021 | Recruiting |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00147433, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Mar 30, 2006 · Synced Sep 7, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00147433 live on ClinicalTrials.gov.