A cross-sectional research of iodine status of pregnant women in Chongqing, south-west China

Objective: To investigate whether implementation of a universal salt iodization (USI) programme has sufficient effects on pregnant women in Chongqing, the present study evaluated the iodine nutritional status of pregnant women living in Chongqing by spot urinary iodine concentration (UIC), to provide scientific suggestions to better meet the specific iodine needs of this vulnerable group. Design: Cross-sectional design. Setting: A random spot urine sample and household table salt sample were provided by each participant. Participants: A total of 2607 pregnant women from twenty-six of thirty-nine districts/counties in Chongqing participated. Results: The overall median UIC of pregnant women was 171 center dot 80 mu g/l (interquartile range (IQR) = 113 center dot 85-247 center dot 00 mu g/l) and 40 center dot 97 % (n 1057) of participants were iodine insufficient. The median iodine in table salt samples was 25 center dot 40 mg/kg (IQR = 23 center dot 10-28 center dot 30 mg/kg); 93 center dot 26 % (n 2406) of samples examined were found to be adequately iodized. Iodine nutritional status was not significantly different according to table salt iodization category. Trimester was identified to be statistically associated with UIC (P < 0 center dot 01). Seven districts/counties had median UIC below 150 mu g/l and one district had median UIC of 277 center dot 40 mu g/l. Conclusions: The USI programme in Chongqing prevents iodine deficiency generally, but does not maintain iodine status within adequate and recommended ranges throughout pregnancy. Usage of non-iodized or unqualified iodized salt and the slight change of dietary habits of iodized salt in Chongqing may present a substantial challenge to fight iodine-deficiency disorders; more efforts are needed to ensure adequate iodine intake during pregnancy besides the USI programme.