Research on Excessive Iodine Status in Pregnancy

February 3, 2018 updated by: Peking Union Medical College Hospital

A Prospective Observational Study on Health Effect of Excessive Iodine Exposure in Pregnancy

To explore main cause and health impact of iodine excess during pregnancy, we performed iodine evaluation for 390 consecutive pregnant women from January 1st, 2016 to December 31st, 2016. Among them, 18 women (4.62%) with apparently elevated urinary iodine concentration (UIC) were enrolled onto this study for subsequent follow-up. History of high iodine exposure was collected from all participants. Parameters about iodine status were monitors until termination of pregnancy, and dietary iodine intake condition and thyroid function were also evaluated.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

A prospective follow-up was arranged for the 18 pregnant women with excessive iodine status. History of iodine exposure (including hysterosalpingography (HSG) using an oil-soluble iodinated contrast medium, examination by computed tomography scan with contrast, administration of amiodarone, history of receiving radioiodine therapy, etc.) was collected from all participants. Evaluation of dietary iodine intake was performed through a 72-hour dietary recall.The serum iodine concentration (SIC) and urinary iodine concentration (UIC) were monitored continuously in the whole course of pregnancy. All subjects with excessive iodine load were recommended by nutritionists to have their dietary iodine intake restricted, and resume iodine-containing supplements and foods until the UIC<250 μg/L and SIC≤90 μg/L. After delivery, maternal colostrum iodine concentration and neonatal iodine status (including neonatal UIC, condition of congenital hypothyroidism screening tests, and thyroid physical examination) were also assessed.

Study Type

Observational

Enrollment (Actual)

18

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

All enrolled pregnant women will be from urban area of Beijing, whose dietary iodine intake and pre-gestational history of iodine exposure will be reviewd in detail.

Description

Inclusion Criteria:

  • Pregnant women with apparently elevated urinary iodine concentration (UIC ≥250μg/L) and serum iodine concentration (SIC>90μg/L) were enrolled in this study.

Exclusion Criteria:

  • Subject who did not sign the informed consent or whose clinical date was not intact was excluded in our study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Only
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
HH group
Group (participants) with pre-gestational history of undergoing hysterosalpingography (HSG) using an oil-soluble iodinated contrast medium
Other: Dietary iodine intake restriction
All subjects with excessive iodine load were recommended by nutritionists to restrict dietary iodine intake, and resume iodine-containing supplements and foods until their iodine status return to normal. However, in this observational study, the intervention was a regular management in prenatal care, and not assigned by investigator of the study.
Non-HH group
Group (participants) without pre-gestational history of undergoing hysterosalpingography (HSG)
Other: Dietary iodine intake restriction
All subjects with excessive iodine load were recommended by nutritionists to restrict dietary iodine intake, and resume iodine-containing supplements and foods until their iodine status return to normal. However, in this observational study, the intervention was a regular management in prenatal care, and not assigned by investigator of the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
prevalence of adverse pregnancy outcome
Time Frame: 6-9 months post identification of maternal iodine excess
prevalence of stillbirth, abortion and other adverse pregnancy outcome
6-9 months post identification of maternal iodine excess
composite neonatal outcome
Time Frame: 6-9 months post identification of maternal iodine excess
Apgar scores, birth weight of the neonates,and prevalence of thyroid dysfunction in neonates
6-9 months post identification of maternal iodine excess

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
prevalence of maternal thyroid dysfunction in pregnancy
Time Frame: through study completion, about 6-9 months post identification of maternal iodine excess
Laboratory reference ranges of TSH during pregnancy were 0.1~2.5 mIU/L for the first trimester, 0.2~3.0 mIU/L for the second trimester and 0.3~3.0 mIU/L for the third trimester.Prevalence of TSH elevation during pregnancy will be summarized.
through study completion, about 6-9 months post identification of maternal iodine excess
prevalence of neonatal iodine excess
Time Frame: within 1 week after birth
urinary iodine concentration will be examined for all neonates born to women with iodine excess in pregnancy, and prevalence of neonatal urinary iodine concentration ≥ 200μg/L will be summarized.
within 1 week after birth

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Peking Union Medical College Hospital

Investigators

  • Study Chair: Xuan Zhang, MD, Department of academic research,Peking Union Medical College Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2016

Primary Completion (Actual)

January 1, 2017

Study Completion (Actual)

March 1, 2017

Study Registration Dates

First Submitted

January 24, 2018

First Submitted That Met QC Criteria

January 30, 2018

First Posted (Actual)

February 5, 2018

Study Record Updates

Last Update Posted (Actual)

February 6, 2018

Last Update Submitted That Met QC Criteria

February 3, 2018

Last Verified

January 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Liuyanping

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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