Iodine Status Monitoring in PortUguese Pregnant woMen: Impact of Supplementation

Study Overview
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Brief Summary
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Data from 2007 regarding iodine status among Portuguese pregnant women indicate this is an iodine deficient population group, with only 16.8% presenting adequate urinary iodine values. This may have serious implications for normal cognitive development of the offspring and a concerning socioeconomic impact. In 2013, concerns by the Portuguese Directorate-General of Health lead to the implementation of a public health policy (nº 011/2013) recommending iodine supplementation during pregnancy. IoMum emerges from this context to monitor and update iodine status in Portuguese pregnant women and to evaluate the effectiveness of the above policy by assessing clinical compliance to iodine supplementation and the impact of iodine supplementation in this vulnerable group. IoMum will update data on iodine nutrition in Portuguese pregnant women, promoting political actions towards the elimination of iodine deficiency and thus to the reduction of nutritional, social and economic inequalities.

Official Title
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Iodine Status Monitoring in PortUguese Pregnant woMen: Impact of Supplementation

Conditions
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Iodine Status in Pregnancy, Iodine Deficiency

Intervention / Treatment
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* Diagnostic Test: Urinary Iodine Concentration Measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women attending the 1st trimester fetal ultrasound scan, from the 10th to the 13th gestational week. Exclusion Criteria: Use of Levothyroxine.
Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| IOMUM<br>Pregnant women | Diagnostic Test: Urinary Iodine Concentration Measurement<br>* UIC<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 1st trimester urinary iodine concentration | Median urinary iodine concentration at 1st trimester of gestation | Between gestational weeks 10 and 13 plus 6 days (one timepoint collection - Timepoint 1) | 
| Rate of compliance to iodine supplementation guideline | Rate of compliance to iodine supplementation guideline at 1st trimester of gestation | Between gestational weeks 10 and 13 plus 6 days (one timepoint collection - Timepoint 1) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in median iodine-to-creatinine ratio | Change in median iodine-to-creatinine ratio between 1st and 3rd trimesters of gestation | Up to 31 weeks | 
| Proportion of pregnant women with insufficient, adequate or excessive iodine intake | Classification of pregnant women by urinary iodine concentration levels according to WHO criteria (insufficient, adequate or excessive iodine intake) at 1st trimester of gestation. | Between gestational weeks 10 and 13 plus 6 days (one timepoint collection - Timepoint 1) | 
| Maternal median thyroglobulin | Maternal median thyroglobulin at 3rd trimester of gestation | Between gestational weeks 35 and 41 (one timepoint collection - Timepoint 2) | 
| 1st trimester mean sodium excretion | Mean sodium excretion at 1st trimester of gestation | Between gestational weeks 10 and 13 plus 6 days (one timepoint collection - Timepoint 1) | 
| 3rd trimester mean sodium excretion | Mean sodium excretion at 3rd trimester of gestation | Between gestational weeks 35 and 41 (one timepoint collection - Timepoint 2) |