17 OH Progesterone Test

The 17-OH progesterone test is used to measure the amount of 17-OH progesterone (17-OHP) in a sample of blood. The test is also known as 17-hydroxyprogesterone test, progesterone-17-OH test, and 17-OHP test.

17-OH progesterone is used by your adrenal glands (the glands on the top of your kidneys) to produce cortisol, a hormone responsible for your body’s energy levels, blood pressure, blood sugar, and response to stress and injury. The 21-hydroxylase enzyme helps convert 17-OH progesterone into cortisol. In people with 21-hydroxylase deficiency, 17-OH progesterone cannot be effectively converted into cortisol and accumulates in the body. A high level of 17-OH progesterone is a sign of an adrenal disorder known as congenital adrenal hyperplasia (CAH). Hence, this test is used by doctors to diagnose, monitor, and check treatment response in CAH.

The 17-OH progesterone test may be recommended for individuals with symptoms of congenital adrenal hyperplasia, as follows:

Symptoms in babies with severe CAH, such as:

• Inability to gain weight
• Diarrhoea
• Lack of energy
• Dehydration
• Vomiting

Symptoms in children and teenagers with mild CAH:

• Severe acne
• Signs of early puberty
• Shorter-than-average height

Symptoms in women with mild CAH:

• Deepening of the voice
• Increase in muscle mass
• Absence of menstrual periods
• Infertility
• Excessive hair growth including facial hair

Symptoms in men with CAH:

• Enlargement of the penis accompanied by small testes
• Fertility-related concerns

The test is also done as part of a routine screening test for babies when they are born.

The test is also highly recommended for the following categories of individuals:

• Females with polycystic ovarian syndrome (PCOS) – In this condition, 17-OH progesterone levels may sometimes be elevated.
• Females with hirsutism – This is a condition in which there is excessive hair growth in females. It is usually seen as a symptom of CAH.

The 17-OH progesterone test can be used along with other tests to diagnose certain conditions, such as:

• Congenital adrenal hyperplasia – This is a genetic disorder of the adrenal gland in which it is unable to make sufficient amounts of hormones, namely cortisol and aldosterone. CAH can be classic (severe form of the disorder) or non-classic (mild form of the disorder).
• Adrenocortical carcinoma – This refers to the cancer of the adrenal gland. It is a rare disorder whose cause is unknown.

The test can also be used to evaluate or rule out certain conditions, such as:

• Polycystic ovary syndrome – This is a condition that affects the ovaries and is caused by an imbalance of hormones.

What to Expect Before the 17-OH Progesterone Test

No fasting is required for a standalone 17-OH Progesterone test. You can eat and drink normally. However, if it is part of a broader package that includes fasting tests, your doctor may advise fasting for 8-12 hours. Avoid strenuous exercise for 24 hours before the test, as intense physical activity can temporarily raise 17-OH Progesterone levels and affect interpretation. Always inform your doctor about any ongoing medications.

What to Expect During the Blood Collection

A phlebotomist cleans the skin with an antiseptic, then places an elastic band around your upper arm to make the veins easier to access. A small needle is inserted into the vein; you may feel a brief pinch. Blood is collected into a labelled tube in under a minute.

What to Expect After the 17-OH Progesterone Test

A small cotton swab and bandage are placed over the site to stop any minor bleeding. You can return to normal activities immediately. Minor bruising is normal and disappears quickly. If dizzy, sit and rest for a few minutes.

In the 17-OHP test, the primary parameter being measured is:

• The level of 17-OH progesterone in a sample of blood.

The 17-OHP normal range is indicated in the table below.

Note: The normal range may vary slightly depending on the laboratory and individual health conditions.

The table below provides a general interpretation of the 17-OH progesterone test results based on whether the levels are low or high.

Like any other medical test, this test also has certain risks and limitations.

Risks:

The 17-OH progesterone test is generally safe and involves minimal risk. You may experience slight pain when the needle is inserted or mild bruising afterwards, which usually resolves spontaneously.

Limitations:

• The 17-OHP test is a screening and diagnostic aid. Abnormal results usually require confirmation with additional tests.
• In newborns, the 17-OHP test cannot check for mild forms of CAH and is only effective for screening classic CAH.
• Timing of blood collection needs to be specific, usually early in the morning, when 17-OHP levels are the highest (normal circadian variation).

Depending on your symptoms and results, your doctor might recommend certain additional tests to better understand your condition. These include:

• ACTH stimulation test
• Amniocentesis
• Chorionic villus sampling
• Serum electrolytes test
• Aldosterone test
• Renin test
• Cortisol test