Iodine Status Monitoring in PortUguese Pregnant woMen: Impact of Supplementation (IOMUM)

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.

Study Overview

• Status: Completed
• Conditions: Iodine Deficiency; Iodine Status in Pregnancy
• Intervention / Treatment: Diagnostic test: Urinary Iodine Concentration Measurement

• Study Type: Observational
• Enrollment (Actual): 485

Contacts and Locations

• Study Contact: Name: Elisa Keating, PhD; Phone Number: 26650 +351 220426650; Email: keating@med.up.pt
• Study Contact Backup: Name: António Soares; Phone Number: 225513622; Email: ajasoares@med.up.pt

Study Locations

• Portugal
  • Porto, Portugal, 4200-319
    • Faculty of Medicine of the University of Porto

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Portuguese pregnant women

Description

Inclusion Criteria:

• Pregnant women attending the 1st trimester fetal ultrasound scan, from the 10th to the 13th gestational week.

Exclusion Criteria:

• Use of Levothyroxine.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
IOMUM; Pregnant women	Diagnostic test: Urinary Iodine Concentration Measurement; UIC

What is the study measuring?

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)

Collaborators and Investigators

• Sponsor: Universidade do Porto
• Collaborators: Hospital de Braga; NOVA Medical School; Centro Hospitalar De São João, E.P.E.; Centro de Investigação em Tecnologias e Serviços de Saúde (CINTESIS); Faculty of Medicine (FMUP)
• Investigators: Principal Investigator: Elisa Keating, PhD, Center for Health Technology and Services Research; Principal Investigator: Conceição Calhau, PhD, Center for Health Technology and Services Research

Publications and helpful links

General Publications

• Matta Coelho C, Guimaraes J, Bracchi I, Xavier Moreira N, Pinheiro C, Ferreira P, Pestana D, Barreiros Mota I, Cortez A, Prucha C, Martins C, Pinto E, Almeida A, Delerue-Matos C, Dias CC, Moreira-Rosario A, Ribeiro de Azevedo LF, Cruz Fernandes V, Ramalho C, Calhau C, Brantsaeter AL, Costa Leite J, Keating E. Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort. J Endocrinol Invest. 2022 Oct;45(10):1865-1874. doi: 10.1007/s40618-022-01813-7. Epub 2022 May 30.

Study record dates

Study Major Dates

• Study Start (Actual): April 17, 2018
• Primary Completion (Actual): September 30, 2020
• Study Completion (Actual): February 28, 2021

Study Registration Dates

• First Submitted: August 3, 2018
• First Submitted That Met QC Criteria: July 5, 2019
• First Posted (Actual): July 8, 2019

Study Record Updates

• Last Update Posted (Actual): October 19, 2023
• Last Update Submitted That Met QC Criteria: October 18, 2023
• Last Verified: July 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: IOMUM

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No