Publication:

Urinary iodine level assessment during third trimester in a sample of Egyptian pregnant women and its relation to thyroid function

Background Inadequate intakes of iodine during pregnancy may cause thyroid dysfunctions that adversely affect pregnancy outcomes. Aim of the work was to evaluate the urinary iodine level as a marker of iodine status in a sample of Egyptian pregnant women during 3rd trimester and assess its relation to thyroid functions.

Methods This cross-sectional study was conducted on 100 pregnant females at their 3rd trimester aged (18-35) years. They were divided according to their urinary iodine concentration into 3 groups; Group (I): Pregnant females with deficient iodine (<150 μg/l), Group (II): Pregnant females with adequate iodine (150-249) μg/l, Group (III): pregnant females including who have above requirements (250-499 μg/l), and excessive (≥500 μg/l). TSH, free t4, free t3, Anti-Thyroglobulin (TgAb) and anti-thyroid perioxidase (TPOAb), medium urinary Iodine concentration (UIC) by ELISA and neck U/S were performed to all participants.

Results 18% of the pregnant women in our study had iodine deficiency during 3rd trimester (UIC<150 ug/l) whereas 55% of pregnant women had excess iodine level, and adequate iodine level was observed in 27%.  Serum TSH was significantly higher in group I with deficient iodine level (p value<0.01). All pregnant women included at group I were suffering from subclinical hypothyroidism. Serum TSH and thyroid volume were inversely correlated with urinary iodine among pregnant females at 3rd trimester (p value<0.01).

Conclusions Serum TSH and thyroid volume were inversely correlated with urinary iodine level among pregnant females at 3rd trimester.