Estimation of thyroid stimulating hormone, total thyroxin and total triiodothyronine during pregnancy, gezira state, central Sudan

Thyroid disease is the second most common endocrine disease affecting women of reproductive age. The current study aimed to assess the effect of pregnancy on thyroid function among Sudanese pregnant women at Wad Medani Police Hospital, Gezira State - Central Sudan. 115 pregnant women, at different stages of pregnancy, were randomly selected as cases. The gestational age was (28 first trimester, 32 second trimester, and 55 third trimester). 30 apparently age-matched and healthy non-pregnant women were selected as control group. 5 ml of venous blood sample were collected from all the recruited cases and controls. Serum was obtained for thyroid stimulating hormone (TSH), total thyroxin (TT4), and total triiodothyronine (TT3) analysis. TT4 concentrations in pregnant women were significantly higher during the second and third trimester (P< 0.05) compared to control group. TSH concentrations showed significant decrease in pregnant women compared to control group, particularly in the third trimester. No significant change was shown in TT3 concentrations. The effect of pregnancy on elevation of T4 and lowering TSH, may lead to misclassification of maternal thyroid function.