Table 1. Description of the studies selected for systematic review.

Authors / Year	Site	Study Design	Recruitment	Sample size (n)	Trimester of pregnancy	Median Urinary Iodine Concentration (UIC) (μg/L)	Median UIC Classification	Prevalence of Iodine Deficiency	Quality of the Studies Included
Amouzegar and Azizi (2013) (19)	Iran	Cross-sectional	Pregnant women referred to the mother and child health care clinics of two maternity hospitals of Tehran	36	First trimester (< 15 weeks)	138.4 (24.1 – 404)	Insufficient	34.0%	16 points