Congenital Adrenal Hyperplasia (CAH) Test: Screening and Diagnosis for Patients and Parents

The congenital adrenal hyperplasia (CAH) test is a blood test that measures the level of 17-hydroxyprogesterone (17-OHP), a hormone made by the adrenal glands. It helps doctors find out whether the body is producing abnormal amounts of certain hormones because of an inherited enzyme deficiency.

The 17-Hydroxyprogesterone (17-OHP) test measures the amount of a hormone called 17-hydroxyprogesterone in a baby's blood. This test is part of the routine newborn screening program, which is performed on all newborns shortly after birth to detect certain genetic and metabolic disorders early.

This test is done to screen for or diagnose CAH, an inherited condition in which the adrenal glands do not make enough cortisol and often produce too much androgen. Early detection matters because severe forms of CAH can cause dangerous salt loss and dehydration in newborns, while milder forms may affect growth and development over time.

This test is primarily used to screen for Congenital Adrenal Hyperplasia (CAH). CAH is a group of genetic disorders that affect the adrenal glands, which produce important hormones like cortisol and aldosterone. Babies with CAH have difficulty producing these hormones and may produce excess androgens (male hormones).

In newborns, a small blood sample is usually taken by pricking the baby's heel a day or two after birth as part of routine newborn screening. In older children and adults, blood is drawn from a vein in the arm with a small needle. The sample is sent to a laboratory, where the hormone level is measured. The procedure takes only a few minutes and causes minimal discomfort.

A small blood sample is taken from the baby's heel (heel stick) or sometimes from the umbilical cord. The blood is then sent to a laboratory for analysis. This is usually done 24-48 hours after birth, before the baby leaves the hospital.

A normal result means the hormone level is within the expected range and CAH is unlikely. An elevated 17-OHP level may suggest congenital adrenal hyperplasia, although results can vary depending on the baby's age, birth weight, or whether the baby was born prematurely. Any abnormal result needs to be confirmed with follow-up testing by a specialist.

Normal 17-OHP levels vary based on the baby's gestational age and birth weight. If the level is higher than normal, it suggests the baby may have CAH. However, a high level does not always mean CAH - it could be due to other factors. If the initial test is abnormal, the baby will need a follow-up test to confirm the diagnosis.

If CAH is confirmed, your doctor will create a treatment plan based on the specific form of the condition. Treatment usually includes hormone replacement medications, such as glucocorticoids, and often mineralocorticoids and salt supplements to replace missing hormones. With early diagnosis and consistent treatment, most people with CAH live healthy, active lives, and regular follow-up visits help keep the condition well controlled.

If CAH is confirmed, treatment can begin immediately. Treatment usually involves medication to replace the missing hormones and prevent complications. With early diagnosis and proper treatment, children with CAH can lead healthy, normal lives.