Serum Thyroglobulin as a Marker of Iodine Status During Pregnancy

Study Overview
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Brief Summary
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The purpose of the investigation is to assess iodine status of pregnant women at week 16 of gestation targeting serum thyroglobulin as a biomarker of iodine deficiency. The investigators aim to assess whether pre-gestational initiation of iodine supplementation is more advantageous in comparison to supplementation start at the time of pregnancy detection.

Detailed Description
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Mild iodine deficiency is still a public health issue in many industrialized countries, especially during pregnancy. During the last decade there was no monitoring of the iodine status in pregnancy in Hungary. Since urinary iodine concentration (UIC) only reflects recent iodine intake and carries limited information on individual existing iodine stores, another biomarker e.g. measurement of serum thyroglobulin concentration, would be useful to gain comprehensive information. In the present study, the purpose of the investigation is to compare UIC, UIC normalized to creatinine concentration and serum thyroglobulin as biomarkers of iodine supply in pregnant women in a geographical region where previously iodine deficiency had been found. UIC, serum thyroglobulin level and thyroid function are measured, and information about iodine supplementation and smoking before and during pregnancy are recorded.

Official Title
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Serum Thyroglobulin as a Marker of Iodine Nutrition Status During Pregnancy in Hungarian Population

Conditions
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Thyroid; Functional Disturbance, Dietary Iodine Deficiency

Intervention / Treatment
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* Dietary Supplement: iodine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy pregnant women at week 16 of gestation Exclusion Criteria: thyroid disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Non-users<br>Pregnant women who had not taken dietary iodine supplement before and during pregnancy. | |
| Users<br>Pregnant women who had taken dietary iodine supplement before and/or during pregnancy. | Dietary Supplement: iodine<br>* ≥ 150 µg/day iodine supplementation (iodine containing pregnancy supplement) prior to enrollment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Urinary iodine concentration | Measurement of urinary iodine concentration (by inductively coupled plasma mass spectrometry) normalized to urine creatinine concentration | At subject enrollment | 
| Serum thyroglobulin concentration | Measurement of serum thyroglobulin concentration by chemiluminescent immunoassay | At subject enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum thyroid stimulating hormone concentration | Measurement of serum thyroid stimulating hormone concentration by electrochemiluminescence immunoassay | At subject enrollment | 
| Serum free thyroxine concentration | Measurement of serum free thyroxine concentration by electrochemiluminescence immunoassay | At subject enrollment | 
| Serum free triiodothyronine concentration | Measurement of serum free triiodothyronine concentration by electrochemiluminescence immunoassay | At subject enrollment | 
| Serum anti-thyroglobulin autoantibody concentration | Measurement of serum anti-thyroglobulin autoantibody (TgAb) concentration by radioimmunoassay (women with TgAb concentration above 60 IU/L are considered TgAb positive) | At subject enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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thyroglobulin, iodine, pregnancy