Group Education to Improve the Iodine Nutrition in Pregnancy: Cluster Randomized Trial

• Iodine deficiency [ Time Frame: 36 weeks of pregnancy ] [ Designated as safety issue: No ]
  Urinary iodine excretion below 150 µg/l
  
  
• Iodine deficiency [ Time Frame: 24 weeks of pregnancy ] [ Designated as safety issue: No ]
  Urinari iodine excretion below 150 µg/l
  
  

• Date of birth [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Smoking [ Time Frame: First trimester of pregnancy (14 weeks) ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodized salt consumption [ Time Frame: First trimester of pregnancy (14 weeks) ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodine supplementation consumption [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Education Level [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  Categories: can not read or write, incomplete primary, completed primary, completed secondary and university
  
  
• Ethnicity [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Number of pregnancies finishes [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Number of premature births [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Number of abortions [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Number of live births [ Time Frame: At baseline ] [ Designated as safety issue: No ]
  
• Trimester of pregnancy [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Glasses of milk a day (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Yogurt per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Servings of cheese per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Usual preparation of vegetables [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Use of water to boil vegetables [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Vegetable consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Fish consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Usual preparation of fish [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Canned tuna consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Canned sardines consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Meat consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Cold meat consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Eggs consumption per week (number) [ Time Frame: First trimester or pregnancy ] [ Designated as safety issue: No ]
  
• Fruit consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Nuts consumption per week (number) [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Potassium iodide consumption [ Time Frame: First trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Smoking [ Time Frame: Second trimester of pregnancy (wk 15-wk 27 ) ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Smoking [ Time Frame: Third trimester of pregnancy (wk28-wk40) ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodized salt consumption [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodized salt consumption [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodine supplementation consumption [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Iodine supplementation consumption [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Trimester of pregnancy [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Trimester of pregnancy [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Glasses of milk a day (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Glasses of milk a day (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Yogurt per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Yogurt per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Servings of cheese per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Servings of cheese per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Usual preparation of vegetables [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Usual preparation of vegetables [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Use of water to boil vegetables [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Use of water to boil vegetables [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: yes / no
  
  
• Vegetable consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Vegetable consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Fish consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Fish consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Usual preparation of fish [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Usual preparation of fish [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  Categories: raw, fried, grilled / baked, steamed and boiled
  
  
• Canned tuna consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Canned tuna consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Canned sardines consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Canned sardines consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Meat consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Meat consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Cold meat consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Cold meat consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Eggs consumption per week (number) [ Time Frame: Second trimester or pregnancy ] [ Designated as safety issue: No ]
  
• Eggs consumption per week (number) [ Time Frame: Third trimester or pregnancy ] [ Designated as safety issue: No ]
  
• Fruit consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Fruit consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Nuts consumption per week (number) [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Nuts consumption per week (number) [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Potassium iodide consumption [ Time Frame: Second trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Potassium iodide consumption [ Time Frame: Third trimester of pregnancy ] [ Designated as safety issue: No ]
  
• Iodine deficiency [ Time Frame: Baseline at first trimester of pregnancy ] [ Designated as safety issue: No ]
  Urinary iodine excretion below 150 µg/l
  
  

BACKGROUND: It is a priority to achieve an adequate nutritional status of iodine during pregnancy since iodine deficiency in this population may have repercussions on the mother during both gestation and post partum as well as on the foetus, the neonate and the child at different ages. According to the WHO, iodine deficiency is the most frequent cause of mental retardation and irrreversible cerebral lesions around the world. However, few studies have been published on the nutritional status of iodine in the pregnant population within the Primary Care setting, a health care level which plays an essential role in the education and control of pregnant women.

AIMS: 1.- To know the hygiene-dietetic habits related to the intake of foods rich in iodine and smoking during pregnancy. 2.- To determine the prevalence of iodine deficiency and the factors associated with its appearance during pregnancy.

METHODS/DESIGN: We will perform a cluster randomised, controlled, multicentre trial. Randomisation unit: Primary Care Team. Study population: 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. Outcome measures: consumption of iodine-rich foods and iodine deficiency. Points of assessment: each trimester of the gestation. Intervention: group education during the first trimester of gestation on healthy hygiene-dietetic habits and the importance of an adequate iodine nutritional status. Statistical analysis: descriptive analysis of all variables will be performed as well as multilevel logistic regression. All analyses will be done carried out on an intention to treat basis and will be fitted for potential confounding factors and variables of clinical importance.

DISCUSSION: Evidence of generalised iodine deficiency during pregnancy could lead to the promotion of interventions of prevention such as how to improve and intensify health care educational programmes for pregnant women.