Thyroid Functional Status in Preeclamptic Women and Pregnancy Outcome: A Cross-Sectional Comparative Study at a Tertiary Care Hospital in Bangladesh

Background: Preeclampsia is a leading cause of maternal and perinatal morbidity in low- and middle-income countries. Thyroid hormones modulate vascular tone and placental function, but Bangladeshi data are limited and findings across studies remain inconsistent. Objective: To compare serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) between preeclamptic and normotensive pregnant women, and to describe the associated obstetric outcome. Methods: Cross-sectional comparative study at Rajshahi Medical College Hospital with the Bangladesh Atomic Energy Commission, Rajshahi, July 2011 to June 2013. Sixty-six preeclamptic and 68 normotensive women at 20-40 weeks of singleton gestation were enrolled by purposive sampling; known thyroid, renal, metabolic and chronic hypertensive disease were exclusions. FT3, FT4 and TSH were measured by enzyme-linked immunosorbent assay. Preeclamptic women were stratified by dipstick proteinuria (Group I, 1+; Group II, 2+ or more). Unpaired t and chi-square tests were used; p<0.05 was significant. Results: Groups were comparable for age, gestational age at sampling and parity. Mean TSH was higher in preeclamptic women (6.16±0.85 versus 1.80±0.08 µIU/ml; p<0.001), whereas FT3 (3.22±0.38 versus 2.89±0.20 pg/ml) and FT4 (1.51±0.20 versus 1.39±0.09 ng/dl) did not differ significantly. Within the preeclamptic group TSH was higher in Group II than Group I (6.67±0.49 versus 5.38±0.70 µIU/ml; p<0.05). Preeclamptic women delivered earlier (34.09±1.04 versus 38.16±1.28 weeks) and underwent caesarean section more often (69.70% versus 29.41%); both p<0.001. Conclusion: Preeclampsia was associated with a raised TSH alongside free thyroid hormones within the laboratory range, a pattern consistent with subclinical hypothyroidism, and with earlier and more frequently operative delivery. The design permits association only.