What is the test for?
This test is done when there have been concerns about puberty, usually when your child seems to be developing earlier or faster than expected for their age.
It may also be done if there are worries that puberty has not started at all.
Who will do the test?
The test is carried out on the Children’s Day Care Unit by a trained nurse.
Do I need to do anything before the test?
There are usually no special preparations. Your child can eat and drink normally.
What happens during the test?
- On arrival at the Day Care Unit, local anaesthetic (magic) cream will be applied to the hands and inner elbows as we will need to insert a cannula (a very fine plastic tube that sits in the vein) to allow us to take several samples of blood.
- When the cannula has been placed, a blood sample will be taken.
- An injection of a hormone (GnRH) is then given through the cannula to stimulate the puberty hormones.
- Following this, two further blood samples are taken from the cannula 20 minutes and 60 minutes later.
- The whole test should be over in about 2 – 3 hours and you will be able to go home after the cannula has been removed.
Are there any side-effects?
Your child should not feel any side-effects from the test.
Other tests your child may need
Sometimes, girls may have an ultrasound scan on the same day as the blood test. This allows us to look at how mature the internal organs (uterus and ovaries) are and helps to show us whether puberty has started. This test will be carried out in the x-ray department and will be fully explained to your child.
When will I get the results of the test?
The results of the test / tests will be discussed with you by the doctor, either by letter or in clinic. Please do not contact the secretary or Day Care Unit for the results as they are not allowed to give out this information. All urgent results will be communicated to you as soon as possible.
Contact details
Secretary to Consultants in Paediatric Endocrinology
Children’s Day Care Unit
Children’s Endocrine Nurse Specialists
This line is not staffed all the time. Please leave your name, your child’s name and date of birth, and a contact number, and someone will get back to you within
24-48 hours. Alternatively you can email us.
