Iodine status in the Last Month of Pregnancy in Iranian Women

Backgrounds: Iodine is a trace element essential for thyroid hormone production. Thyroid hormones play a key role in normal fetal brain development. In-utero iodine deficiency can lead to irreversible cognitive and motor deficits. This study was performed for the first time on iodine status in the last month of pregnancy in Iranian women.Material and Method : This cross-sectional study was performed on 214 women in their last month of pregnancy in the city of Shiraz. Subjects were chosen from pregnant women referring to 4 major hospitals and 5 OB/GYN clinics for normal follow up. Inclusion criteria were confirmed last month of pregnancy and being in good general health without thyroid disorders, other chronic illnesses, or medications. A morning spot urine was taken from the subjects and sent for a single laboratory. Urine iodine concentration was (UIC) measured using the Sandell-Kolthoff method. WHO reference medians were used to classify iodine status as insufficient (<150 μg/l), adequate (150–249 μg/l), above requirements (250–499 μg/l) or excessive (≥500 μg/l).Result: Overall median UIC (IQR) in the participants was 112.10 (92.05-134.60) μg/l. Median UIC in gestational age of 36 (n=44), 37 (n=58), 38 (n=47), 39 (n=36) and 40 (n=29) was 121.95 (100.83-149.13), 113.25 (94.30-137.20), 111.70 (89.10-128.70), 104.65 (85.05-129.15) and 111.30 (88.20-123.90) ) μg/l respectively. There was a statistically significant decline in iodine concentration in higher gestational ages (p=0.035). 12.6% of overall participants and 25%, 13.8%, 6.4%, 11.1% and 3.4% of participants in gestational age of 36-40 weeks respectively had ≥150 μg/l UIC. This difference was also significant (p=0.038).Conclusion: Iodine deficiency has occurred in Iranian women in their last month of pregnancy. It appears universal salt iodization and seldom prescription of iodofolic supplements may not be enough to combat iodine deficiency in Iran. A comprehensive plan to fight iodine insufficiency in pregnant women should be studied