Profile of thyroid function and urinary iodine excretion of pregnant women attending Harare Central Hospital antenatal clinic

Abstract

A preliminary study to determine the iodine status of pregnant women was carried out in the busy referral antenatal clinic of the Harare Central Hospital. Serum free triiodothyronine (FT3), free thyroxine (FT4), thyrotrophin (TSH), and urinary iodine, were determined in 100 pregnant women, and compared with non-pregnancy control levels. Visible goitres were observed in 16 percent of the pregnant women, and 70 percent of the serum FT3 results fell below the mean value for the non-pregnancy controls. The mean serum FT4 levels were significantly increased. The serum TSH values of the pregnant and the non pregnant women showed no significant differences. No significant differences were observed between the pregnant goitrous and pregnant non-goitrous women with regard to FT3, FT4 and TSH. The urinary iodine concentration was found to be slightly higher in the goitrous pregnant women than in the non-goitrous counterparts. In 40 percent of the pregnant women the urinary iodine concentration was below 100 micrograms I/g creatinine, and in the 0-25 micrograms I/g creatinine range were 15 percent of the total patient sample.