Thyroid function in pregnant Saudi women: A cross-sectional study at a tertiary hospital

BACKGROUND: Thyroid dysfunction during pregnancy can have significant implications for both maternal and fetal health. The physiological changes of pregnancy, including increased thyroxine-binding globulin and human chorionic gonadotropin-mediated thyroid-stimulating hormone (TSH) suppression, alter thyroid hormone concentrations and highlight the need for population-specific reference ranges. This study aimed to characterize trimester-specific thyroid function patterns and hypothyroidism in Saudi pregnant women. MATERIALS AND METHODS: This cross-sectional study was conducted among Saudi women who delivered singleton live births during January1 and December31, 2023 at a tertiary care hospital in Riyadh, Saudi Arabia. A random sample of 329 women meeting the inclusion criteria was selected from a total of 2259 women who delivered during the study period. Data regarding patient demographic characteristics, thyroid disease history, TSH levels, thyroid peroxidase antibody (TPO-Ab) status, and the use of levothyroxine was abstracted from hospital’s electronic health record system using a structured data collection sheet. Data were analyzed using SPSS; Categorical variables were summarized as frequencies and percentages, whereas mean and standard deviation was calculated for continuous variables. Categorical variables were summarized as frequencies and percentages. Thyroid function parameters were compared across clinical groups using ANOVA or Kruskal-Wallis test, as appropriate. RESULTS: Thyroid dysfunction was identified in 27.4% of the 329 Saudi pregnant women; 21.6% of these were subclinical, and 5.8% were overt hypothyroidism. Median TSH concentrations were 2.03, 2.46, and 2.26 mIU/L across the first, second, and third trimesters, respectively. The mean TSH levels differed significantly across thyroid function groups in all trimesters (P<0.01). TPO-Ab positivity was uncommon (5.2%), and levothyroxine was used by 31.0%. CONCLUSION: A notable proportion of Saudi pregnant women exhibited thyroid dysfunction, underscoring the importance of locally derived trimester-specific TSH data. These findings provide useful baseline information that could guide future multicenter or prospective studies and support the refinement of thyroid screening practices in Saudi Arabia.