Prevalence of Thyroid Dysfunction and Thyroid Hormone Levels ‎Among Pregnant Women in Tripoli, Libya: A Cross-Sectional Study

Purpose: To determine the prevalence of thyroid hormone abnormalities and describe the distribution of thyroid-stimulating hormone (TSH), total triiodothyronine (T3), and total thyroxine (T4) concentrations across pregnancy trimesters among pregnant women attending care in the Tripoli region of Libya.

Materials and Methods: This cross-sectional study enrolled 168 pregnant women aged 18–45 years between February 2025 and February 2026. Serum TSH, total T3, and total T4 were measured using an iFlash 1800 automated chemiluminescence immunoassay analyser and categorised against the laboratory's reference intervals (TSH 0.4–4.0 µIU/mL; total T3 0.8–2.0 nmol/L; total T4 57.9–150.6 nmol/L). Data were analysed using SPSS version 20, and mean hormone concentrations were compared descriptively across the three pregnancy trimesters.

Results: Participants were distributed across the first (39.9%), second (31.5%), and third (28.6%) trimesters. Abnormal results were found in 5.95% of women for TSH (3.57% above range, 2.38% below range), 3.57% for total T3, and 1.19% for total T4. Mean TSH concentrations were broadly similar across trimesters (2.03 ± 0.89, 1.90 ± 1.72, and 2.50 ± 1.77 µIU/mL in the first, second, and third trimesters, respectively), whereas total T3 (1.36 ± 0.49, 0.94 ± 0.14, and 1.18 ± 0.59 nmol/L) and total T4 (71.50 ± 19.75, 84.13 ± 25.32, and 76.16 ± 22.99 nmol/L) concentrations showed clearer trimester-to-trimester variation, with total T3 lowest and total T4 highest in the second trimester.

Conclusion: Overall thyroid hormone abnormalities were relatively uncommon in this cohort, but total T3 and total T4 concentrations varied noticeably across pregnancy trimesters. These findings support continued antenatal thyroid screening and highlight the need for larger, multicentre Libyan studies incorporating trimester-specific reference intervals. (Open J Biomed Res 2026;5:114-122)