Research on Excessive Iodine Status 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.

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Key information

Conditions

Excessive Iodine Status Congenital, Hereditary, and Neonatal Diseases and Abnormalities Infant, Newborn, Diseases Neonatal Disorder Pregnancy Related Thyroid Dysfunction, Antepartum

Sex eligibility

Female

Study type

Observational

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Dietary iodine intake restriction

Other

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.

Primary outcomes

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
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

Secondary outcomes

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.
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.

Sponsors and collaborators

Lead sponsor

Peking Union Medical College Hospital

Other

Registry information

Official study title

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

Important dates

Study start: 2016
Primary completion: 2017
Study completion: 2017
First posted: Feb 5, 2018
Registry last updated: Feb 6, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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