Excessive Iodine Status, Neonatal Disorder, Pregnancy Related, Thyroid Dysfunction, Antepartum
Conditions
Keywords
Iodine excess, Cause, Pregnancy, Urinary iodine concentration, Serum iodine concentration, Breast milk iodine concentration
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.
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.
Interventions
OTHERDietary 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.
Sponsors
Peking Union Medical College Hospital
Study design
Observational model
CASE_ONLY
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Outcome results
None listed