Normal Range of TSH and FT4 in Pregnancy

Completed

• Conditions: Hypothyroidism; Pregnancy Related; Thyroid; Dysfunction; Iodine Deficiency
• Interventions: Diagnostic Test: Serum thyroid function tests

• Registration Number: NCT04860622
• Lead Sponsor: Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital

Brief Summary

Physiological changes necessitate the use of pregnancy-specific reference ranges for thyrotrophin (TSH) and free T4 (FT4) to diagnose thyroid dysfunction during pregnancy. Although many centers use fixed upper limits for TSH of 2.5 or 3.0 mU/L, this may lead to overdiagnosis or even overtreatment.

The new guidelines of the American Thyroid Association have considerably changed recommendations regarding thyroid function reference ranges in pregnancy accordingly. Any hospital or physician that is still using the 2.5 or 3.0 mU/l cut-off for TSH during pregnancy should evaluate their own lab-specific cut-offs.

The investigator's objective is to establish a rational reference range of serum TSH for the diagnosis of subclinical hypothyroidism in the first, second, and third trimester of pregnant women in the Sancaktepe region in Turkey.

Detailed Description

Serum thyroid function tests (including T3, T4, TSH, Anti-TPO) will be obtained from the singleton pregnancies in the first, second, and third trimester to determine the local specific normal ranges.

Study Timeline

• Study Start: 2021-04-01
• Study First Submitted: 2021-04-22
• Study First Submitted QC: 2021-04-22
• Study First Posted: 2021-04-27
• Primary Completion: 2021-08-15
• Status Verified: 2021-09
• Study Completion: 2021-09-01
• Last Update Submitted: 2021-09-23
• Last Update Posted: 2021-09-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 528

Inclusion Criteria

• Singleton pregnancy
• Free of pre-existing thyroid disease
• That do not use thyroid interfering medication
• That did not undergo IVF treatment
• TPOAb negative

Exclusion Criteria

• Adolescent pregnancy
• Patient with pre-existing thyroid disease
• TPOAb positive
• Patient using thyroid interfering medication
• That had IVF treatment

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Pregnant women	Serum thyroid function tests	500 pregnant women with a singleton pregnancy, free of pre-existing thyroid disease, that do not use thyroid interfering medication, that did not undergo IVF treatment, and are TPOAb negative. Serum thyroid function tests will be obtained on the first visit.

Primary Outcome Measures

Name	Time	Method
TSH	On day 1	Trimester specific TSH level

Secondary Outcome Measures

Name	Time	Method
free T4	On day 1	Trimester specific free T4 level

Trial Locations

Locations (1)

Sehit Prof Dr Ilhan Varank Sancaktepe Training and Research Hospital; 🇹🇷 Istanbul, Turkey