Determination of the Iodine Status in Pregnant Women in the Netherlands. (JOZO)

Determination of the Iodine Status in Pregnant Women in the Netherlands. Are Current Iodine Intake Recommendations Still Adequate?

Study to determine iodine status in dutch pregnant women

Study Overview

• Status: Terminated
• Conditions: Healthy; Pregnancy Related

Detailed Description

Rationale: Adequate dietary iodine intake is essential to thyroid hormone synthesis, which is key for normal growth, development and metabolism. During pregnancy, maternal iodine needs are increased (recommended intake: 175 µg/day) and iodine deficiency during pregnancy affects brain and cognitive development of the foetus and might lead to pregnancy complications. Despite the use of iodized salt, it has been shown that iodine intake in the Netherlands is declining. Importantly, a recent small study in Groningen indicated a high prevalence of iodine deficiency during pregnancy (83% of participants) which was not completely restored by 16-week iodine supplementation (150 ug/d). Also in other Western European countries (i.e. Belgium, U.K., North Ireland, Sweden, Denmark and Austria) low median urinary concentrations of iodine (73-124 ug/L) have been observed in pregnant women. Notably, most studies collected spot-urine samples and a 24h urine collection, the golden standard for determination of iodine status, is lacking. Therefore, here it is proposed to measure 24h median urinary iodine concentration corrected for urinary volume and creatinin levels in pregnant women, and compare these values with Thyroglobulin (Tg)-concentrations in serum as measure for iodine intake over a longer period of time. It is hypothesised that the iodine status of pregnant women in The Netherlands is lower than the national recommended intake for this target group.

• Study Type: Observational
• Enrollment (Actual): 43

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands, 6225 HX
      • Maastricht UMC+

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Healthy pregnant women, under 16 weeks of gestational age living in the Netherlands

Description

Inclusion Criteria:

• Female
• 18-45y old
• in first 16 weeks of pregnancy
• pregnant of singleton

Exclusion Criteria:

• Thyroid-disease or any other metabolic disease
• kidney disease
• twin-pregnancy

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Total cohort; No intervention, all participants undergo the same measurements

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Median urinary iodine excretion (µg/d)	Median urinary iodine excretion (µg/d)	At baseline measurement

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thyroglobulin and thyroglobulin antibody concentrations in blood serum	Thyroglobulin and thyroglobulin antibody concentrations in blood serum	At baseline measurement
Creatinin concentration in urine	Creatinin concentration in urine	At baseline measurement
Urinary volume	Urinary volume	At baseline measurement
Smoking status (smoking is interfering with iodine metabolism)	Smoking status (smoking is interfering with iodine metabolism) Yes/no	At baseline measurement
Vegan/Vegetarian y/n (soy is competitive for iodine on thyroid)	Vegan/Vegetarian y/n (soy is competitive for iodine on thyroid)	At baseline measurement
Nutritional intake specifically related to iodine intake (questionnaire)	Nutritional intake specifically related to iodine intake (questionnaire) Iodine specific ffq	At baseline measurement
Intake other relevant micronutrients for pregnant	Intake other relevant micronutrients for pregnant	At baseline measurement

Collaborators and Investigators

• Sponsor: Maastricht University Medical Center
• Collaborators: National Institute for Public Health and the Environment (RIVM)

Study record dates

Study Major Dates

• Study Start (Actual): October 6, 2020
• Primary Completion (Actual): May 1, 2024
• Study Completion (Actual): May 1, 2024

Study Registration Dates

• First Submitted: December 16, 2022
• First Submitted That Met QC Criteria: May 8, 2024
• First Posted (Actual): May 14, 2024

Study Record Updates

• Last Update Posted (Actual): June 11, 2024
• Last Update Submitted That Met QC Criteria: June 10, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: NL70677.068.19; NL8297 (Registry Identifier: NL trial register (NTR))

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