NCT06653907

Levothyroxine Intervention in Pregnant Women with TSH （2.5 MIU/L-upper Limit of Reference Range） and Negative Thyroid Peroxidase Antibody

Randomized Control Study of Levothyroxine Intervention in Pregnant Women with Thyroid Stimulating Hormone Between 2.5 MIU/L and Upper Limit of Reference Range and Negative Thyroid Peroxidase Antibody

• Status: Not Yet Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 400 (estimated)
• Sponsor: Yang ZHANG · Academic / Other
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to learn if levothyroxine (L-T4) works to treat pregnant women with TSH 2.5 mIU/L-the upper limit of reference range (ULRR) of pregnancy and TPOAb-negative. It will also learn about the safety of L-T4. The main quesitons the investigator want to answer are: * Will L-T4 reduce miscarriage rates and have an impact on pregnancy complications in pregnant participants? * What medical issues do participants have when taking L-T4 during pregnancy? -Investigators will compare L-T4 with placebo (a substance with a similar appearance without medication) to see if L-T4 could reduce miscarriage rates Participants should: * Take L-T4 or placebo during the whole pregnancy. * Visit the hospital once every 6-8 weeks during pregnancy for checkups and tests * Keep a diary of their pregncny complications and daily record of L-T4 or placebo intake. * Visit the hospital for examination 42 days postpartum for checkups and follow up by phone at 6 and 12 months postpartum.

Conditions

• Thyroid Abnormalities
• Pregnant Woman
• Pregnancy Outcomes

Interventions

Type	Name	Description
DRUG	Levothyroxine Sodium (LT4) Tablets	Participants in our study will determine the dosage of L-T4 based on their weight (BW): 1. BW ≥50kg: Starting with a daily dose of 1 tablet; 2. BW \< 50kg: Starting with a daily dose of half a tablet. At 12 weeks, 18-20 weeks, 24-26 weeks, and 34-36 weeks of gestation, the serum TSH, FT3, and FT4 will be measured, and investigator will adjust dosage according to TSH: 1. When TSH \> ULRR, the participants will receive L-T4 in addition to their original medication, and additional unplanned follow-up; 2. When TSH at 2.5mIU/L-ULRR, add 1/4 tablet of medictaion; 3. When TSH at LLRR -2.5mIU/L, maintain the original dose; 4. When TSH \<LLRR, reduce 1/4 tablets of medictaion. 5. If TSH continues to be lower than LLRR after discontinuation, investigator will measure FT4, TRAb and other indicators to determine if it is clinical hyperthyroidism. If so, antithyroid drugs will administered according to guidelines. Participants will stop all trial medictaion after delivery.
DRUG	Placebo	Participants in our study will determine the dosage of placebo based on their weight (BW): 1. BW ≥50kg: Starting with a daily dose of 1 tablet; 2. BW \< 50kg: Starting with a daily dose of half a tablet. At 12 weeks, 18-20 weeks, 24-26 weeks, and 34-36 weeks of gestation, the serum TSH, FT3, and FT4 will be measured, and investigator will adjust dosage according to TSH: 1. When TSH \> ULRR, the participants will receive L-T4 in addition to their original medication, and additional unplanned follow-up; 2. When TSH at 2.5mIU/L-ULRR, add 1/4 tablet of medictaion; 3. When TSH at LLRR -2.5mIU/L, maintain the original dose; 4. When TSH \<LLRR, reduce 1/4 tablets of medictaion. 5. If TSH continues to be lower than LLRR after discontinuation, investigator will measure FT4, TRAb and other indicators to determine if it is clinical hyperthyroidism. If so, antithyroid drugs will administered according to guidelines. Participants will stop all trial medictaion after delivery.

Timeline

• Start date: 2024-10-25
• Primary completion: 2026-12-31
• Completion: 2027-10-31
• First posted: 2024-10-22
• Last updated: 2024-10-23

Locations

1 site across 1 country: China