This study will investigate if there is a beneficial effect of taking extra iodine during pregnancy for the psychomotor development of children. This effect is possibly insignificant for a single child but very small effects may be of importance amongst larger groups. There are already a lot of guidelines to follow during pregnancy which is why we must collect evidence and research facts for coming national decisions. Please read more under About the study.
Because sometimes both parents/caregivers don’t come to the visit together and in order to follow up with the child, there is a requirement that both certify their agreement for the child participating in the study. A new agreement is also collected when the child Is 14 years old. This is because a long time has passed since the last follow-up and the child will be increasingly involved in the decision as the child gets older.
Taking part in the study is completely voluntary and you can end your participation at any time.
When the child is 18 months old you will fill in a web questionnaire regarding living conditions, background factors, and the child’s development (there could also be a short telephone interview). At 3.5 years old you will get a call for a visit where a urine test is taken, and you will also meet a psychologist who will test and assess the child´s development. This visit takes about 1.5-2 hours. The same procedure will be done when the child is 7 years old and 14 years old. A blood test is then also taken along with an examination with a physiotherapist for physical tests. This visit takes 2-3 hours.
Please read more under Children follow-up.
You can absolutely continue but is important to inform the midwife which period this was.
You can absolutely continue.
There is no knowledge today if mild iodine deficiency has any negative consequences for the child and studies that have been done so far have not shown this. The participation in the group who takes the vitamin without iodine is not differing from the recommendations from the Swedish Food Agency regarding iodine and is considered to be without risks.
The tablets which are used in the study contain such a low dose that there is no such risk.
Yes, one of the tablets contains 200 µg of folic acid while the other does not. Which one you will get is impossible to know because this is a blind study. We, therefore, recommend that you take your ordinary supplement of folic acid during the pregnancy when you participate (that is 400 µg folic acid during the first trimester) alongside the study medicine. This means that you will take at most 600 µg folic acid a day, which is lower than the highest tolerable dose of 1000 µg a day.
Yes, folic acid and iron are okay but no others. This is because other dietary supplements may contain iodine or other substances that can influence thyroid gland function. We want to avoid this because the results may be difficult to interpret. Both folic acid and iron are found in one of the tablets, but the amount is so small that there is no risk of too high a dose.
You cannot be included in the study if you take Levaxin from the start of the study but if you get your diagnosis later on you can start with Levaxin during the study.
Yes, every person in Sweden is recommended to use iodine substituted salt and use it in their cooking.
If something shows pathologic signs of the mother or child that need to be more examined (that is something that can indicate eventual disease), we will of course give information to the woman/parents.
If you move, you must inform us. Contact information is found under Contact. Sometimes it is possible to arrange a follow-up in another city so that you may still be able to participate.