17-OH progesterone is a blood test routinely given to newborns in the United States to detect congenital adrenal hyperplasia (CAH). CAH is a glandular disorder that produces an imbalance of the male sex hormone androgen.
CAH can sometimes be visually detected at birth due to ambiguous genitalia, pubic hair, or acne. It can also develop later in life in less obvious ways. Some examples include clearly defined muscle tone, increased body hair, and a deeper voice.
A 17-OH progesterone test (sometimes referred to as 17-OHP) should be part of every infant’s initial medical examination.
The 17-OHP test is important for all newborn babies. However, it should also be considered for anyone who develops a milder, late-onset form of the disorder later in life.
Signs and symptoms of CAH in infants of either sex include:
- genitals that are ambiguous (not clearly male or female)
- pubic hair
- a lack of energy
- disinterest in eating
- low blood pressure
Signs and symptoms in young girls and adult women include:
- irregular periods
- deep voice
- genitalia that has both male and female characteristics, but appear more male
- excessive hair growth
- early hair growth in the pubic and armpit area
Signs and symptoms in young boys and adult men include:
- early onset of puberty, beginning as early as 2 to 3 years of age
- deep voice
- well-defined muscles
- large penis and small testes
Keep in mind that anyone who has been identified with CAH should be tested periodically to monitor his or her condition.
Your doctor may ask you to stop eating eight hours before the exam to secure accurate test results. Fasting is usually not necessary for infants. However, check with the doctor for further directions.
You may need to temporarily stop taking medication that could affect the final lab reports. Birth control pills and steroid hormones called corticosteroids, for example, may affect test results. Consult your physician about your prescribed or over-the-counter medications.
The 17-OHP test is administered like all blood tests. A medical professional will draw blood from a vein in your arm using a needle. A simple fingerprick is enough to provide an adequate blood sample for infants and small children.
Risks involved with the 17-OHP test are similar to any other blood test. Obtaining a sample can be simple or difficult, depending on the size of the veins in your arms.
During the blood test, you might experience a period of lightheadedness. You may have a small bruise at the site of needle insertion.
Because testing has so many variables (age, gender, and testing methods), it is difficult to identify normal and abnormal test results. Make sure to sit down with your doctor to discuss how the 17-OHP test is specifically relevant to you.
Generally, a high concentration of 17-OHP may indicate that the child has CAH or an adrenal tumor.