Research on Excessive Iodine Status in Pregnancy

Sponsor

Peking Union Medical College Hospital (Other)

Overall Status

Completed

CT.gov ID

NCT03422406

Collaborator

(none)

Enrollment

Actual Duration (Months)

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Excessive Iodine Status Thyroid Dysfunction, Antepartum Pregnancy Related Neonatal Disorder	Other: Dietary iodine intake restriction

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 Design

Study Type:

Observational

Actual Enrollment :

18 participants

Observational Model:

Case-Only

Time Perspective:

Prospective

Official Title:

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

Actual Study Start Date :

Jan 1, 2016

Actual Primary Completion Date :

Jan 1, 2017

Actual Study Completion Date :

Mar 1, 2017

Arms and Interventions

Arm	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.

Arm

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

Outcome Measures

Primary Outcome Measures

prevalence of adverse pregnancy outcome [6-9 months post identification of maternal iodine excess]
prevalence of stillbirth, abortion and other adverse pregnancy outcome
composite neonatal outcome [6-9 months post identification of maternal iodine excess]
Apgar scores, birth weight of the neonates,and prevalence of thyroid dysfunction in neonates

Secondary Outcome Measures

prevalence of maternal thyroid dysfunction in pregnancy [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 [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.

Eligibility Criteria

Criteria

Ages Eligible for Study:

N/A and Older

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

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.