Children follow-up

18 months

When the child is 18 months old, you will be contacted for a short telephone interview (approximately 5 minutes) about living conditions and we will send a link with a questionnaire on background factors and the child's development via email or text message which you fill out and send back.

3.5 years

At the age of 3.5, you are called to a physical visit where we measure height, weight, and head circumference. The child may also leave a urine sample where we measure the amount of iodine. During the visit, the child will meet a psychologist for about 1 hour who will assess the children's development and ability. The examination at 3.5 years of age is estimated to take 2 hours.

Before the physical visit, we will send out a link with a questionnaire about background factors and the child's development via email or text message that you fill out and send back.

7 years

At the age of 7, you are called to a physical visit where we measure height, weight, and head circumference. The child may also leave a urine sample where we measure the amount of iodine and we take a blood sample (5-10ml = 1-2 teaspoons). The blood sample is used to measure thyroid hormone and related substances. The sample is taken by experienced healthcare professionals.

During the visit, the child will meet a psychologist for about 1 hour who will make an assessment of the children's development and ability.

They will also meet with a physiotherapist who assesses the child's motor skills. The examination at the age of 7 is estimated to take 2.5-3 hours.

Before the physical visit, we will send out a link with a questionnaire about background factors and the child's development via email or text message that you fill out and send back.

14 years

The child, together with the guardians, can choose whether they want to continue in the study.

At the age of 14, you are called to a physical visit where we measure height, weight, and head circumference. The child may also leave a urine sample where we measure the amount of iodine and we take a blood sample (5-10ml = 1-2 teaspoons). The blood sample is used to measure thyroid hormone levels and related substances. The sample is taken by experienced healthcare professionals.

During the visit, the child will meet a psychologist for about 1 hour who will make an assessment of the children's development and ability.

They will also meet with a physiotherapist who assesses the child's motor skills. The examination at the age of 14 is estimated to take 2.5-3 hours.

Before the physical visit, we will send out a link with a questionnaire about background factors and the child's development via email or text message that you fill out and send back.

Magnetic resonance imaging (MRI)

Under certain circumstances, a small proportion of the children, about 200, will be offered to participate in an MRI of the brain without contrast. The magnetic camera examination takes 20 minutes. Such an examination does not cause radiation but uses magnetic fields. The child lies down on a platform and wears ear protection during the examination, as the machine slams. The MRI tunnel can be a bit cramped for some, but parents and staff are nearby. The MRI provides information about the volume of different parts of the brain.