Torres 2010.

Trial name or title	Nutritional status of iodine in the pregnant population of Catalonia: a study dietary habits and urinary iodine
Methods	Cluster randomised, controlled, multicentre trial. Randomization unit: Primary Care Team. Statistical analysis: descriptive analysis of all variables will be performed as well as multilevel logistic regression. All analyses will be carried out on an intention‐to‐treat basis and will be fitted for potential confounding factors and variables of clinical importance
Participants	898 pregnant women over the age of 17 years attending consultation to a midwife during the first trimester of pregnancy in the participating primary care centres
Interventions	Intervention group: group education during the first trimester of gestation on healthy hygiene‐dietetic habits and the importance of adequate iodine nutritional status Control group: Usual care
Outcomes	Primary outcomes: iodine deficiency (urinary iodine excretion below 150 µg/L) at 24 and 36 weeks of pregnancy Secondary outcome: many including iodized salt consumption, iodine supplementation consumption, and consumption of iodine‐rich foods
Starting date	November 2008
Contact information	Principal Investigator: Maria Teresa Torres Costa, Midwife, Institut Català de la Salut (ICS)
Notes	None

BMIC: breast milk iodine concentration
 FT4: free thyroxine
 Tg: thyroglobulin
 TPO‐ab: thyroid peroxidase antibodies
 TSH: thyroid stimulating hormone
 UIC: urinary iodine concentration