ABSTRACT:
Pregnancy is associated with physiological changes in thyroid function. We aimed to assess iodine status and thyroid
dysfunction among pregnant women. 150 pregnant women were analyzed for serum and urinary iodine levels, free
tri-iodothyronine hormone (FT3), free thyroxine hormone (FT4), thyroid stimulating hormone (TSH),
thyroperoxidase antibodies (TPO-Abs), thyroglobulin antibodies (TG-Abs), total antioxidant status (TAS) and
antioxidant enzymes as superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured. The3rd
trimester pregnant women declined urinary and serum iodine by -37.5% and -36.6%, respectively. Mild serum
iodine deficiency was detected during 1st trimester, 4% (2/50) and more deficiency was detected during 2nd and 3rd
trimester 18% (9/50) and 24% (12/50), respectively. The FT3 and FT4 levels of 3rd trimester were declined by -
14.7% and -30.6%, respectively, and accompanied with increment in TSH by +80.4%. TPO-Abs was elevated
among 2nd and 3rd trimester by +216.7% and +244%, respectively. TG-Abs was elevated among 2nd and 3rd trimester
by +47.4% and 87.1% respectively. 3rd trimester decreased SOD, GPx and TAS by -28.6%, -36.1% and -30%,
respectively. 1st and 2nd trimester declined GPX by -16.7% and -26.6%, respectively. Positive correlation between
urinary and serum iodine, negative correlation between TSH and each of FT3 and FT4, positive correlation between
TPO-Abs and urinary iodine and negative correlation between TPO-Abs and serum iodine were detected. We
conclude that mild thyroid hormones, iodine levels and oxidative stress abnormalities were detected among pregnant
women. These findings lead us to recommend the measuring of iodine and thyroid hormones levels as a routine
check-up to avoid adverse effects on maternal thyroid function.