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Normal Range of TSH and FT4 in Pregnancy

Normal Range of TSH and FT4 in Pregnancy

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT04860622
Acronym
NRTSHTURKEY
Enrollment
528
Registered
2021-04-27
Start date
2021-04-01
Completion date
2021-09-01
Last updated
2021-09-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dysfunction, Hypothyroidism, Iodine Deficiency, Pregnancy Related, Thyroid

Keywords

Hypothyroidism, Pregnancy, trimester, thyroid dysfunction, iodine level

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.

Interventions

DIAGNOSTIC_TESTSerum thyroid function tests

At the first hospital visit, the blood tests will be made for TSH, FT4, FT3, and beta HCG concentration measurement

Sponsors

Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 50 Years

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

Design outcomes

Primary

MeasureTime frameDescription
TSHOn day 1Trimester specific TSH level

Secondary

MeasureTime frameDescription
free T4On day 1Trimester specific free T4 level

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026