A study to establish gestation-specific reference intervals for thyroid function tests in normal singleton pregnancy.

Area of Science:

• Endocrinology
• Obstetrics and Gynecology
• Reproductive Medicine

Background:

• Thyroid function tests (TFTs) are crucial for monitoring maternal and fetal health during pregnancy.
• Existing TFT reference intervals may not accurately reflect physiological changes throughout gestation.
• Accurate TFT interpretation is vital for diagnosing and managing thyroid dysfunction in pregnant individuals.

Purpose of the Study:

• To establish precise, gestation-specific reference intervals for key thyroid hormones.
• To provide a clinical tool for improved diagnosis and management of thyroid disorders in pregnancy.
• To analyze thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (fT3) levels across pregnancy.

Main Methods:

• A cross-sectional observational study involving 335 pregnant women.
• Blood samples were collected to analyze TFTs at various gestational ages.
• Statistical analysis was performed to calculate 95% reference intervals for each hormone per gestational week.

Main Results:

• Gestation-specific 95% reference intervals were successfully calculated for FT4, fT3, and TSH.
• These intervals provide a detailed range for each hormone at every week of pregnancy.
• The data facilitates a more accurate assessment of thyroid status during gestation.

Conclusions:

• The study successfully generated comprehensive, gestation-specific reference intervals for TFTs.
• These established intervals will enhance the clinical management of thyroid disease in pregnant populations.
• Accurate interpretation of thyroid function during pregnancy is now better supported by these findings.