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

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

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.

Sponsors & Collaborators

• National Research Institute for Family Planning, China

  collaborator OTHER_GOV

• The Fourth Hospital of Shijiazhuang

  collaborator OTHER

• Yang ZHANG

  lead OTHER

Principal Investigators

• Ying Gao, Professor · Endocrinology Department of Peking University First Hospital

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

FEMALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-10-25

Primary Completion

2026-12-31

Completion

2027-10-31

Countries

• China

Study Locations