What to Know About the 17 Hydroxyprogesterone Test

Medically Reviewed by Carol DerSarkissian, MD on February 12, 2024
3 min read

The 17-hydroxyprogesterone test measures the amount of 17 OHP or 17 hydroxyprogesterone in your blood. The adrenal glands, located on the top of both your kidneys, make this hormone. They also make a couple of other hormones, including cortisol, known as the stress hormone. Cortisol controls other bodily functions, such as regulation of blood sugar, immune responses, and blood pressure. 

17-OHP is needed to make cortisol. Healthcare providers also check 17-hydroxyprogesterone levels to diagnose a genetic disorder known as congenital adrenal hyperplasia. This disease causes defects during the development of sex organs. It may also hinder the proper development of specific sexual characteristics. 

People have this disorder as the result of a mutation or genetic change that takes place in the body. 

This change does not allow adrenal glands to make the amount of cortisol the body needs. Since the adrenal glands have to work extra hard, they produce a lot of 17-OHP. 

Thus, hydroxyprogesterone levels in the blood rise. A higher 17-OH progesterone level indicates the presence of the disease.

Doctors recommend the 17-OH progesterone test for all babies to rule out the possibility of them having congenital adrenal hyperplasia. If adults develop other symptoms of the disease, the 17-Hydroxyprogesterone test is performed to diagnose the problem. 

Some signs of CAH in children are acne, ambiguous (not clearly female or male)genitals, lack of interest in eating, dehydration, vomiting, pubic hair, and low blood pressure. In young women, the signs include a deep voice, excessive hair growth, irregular periods, and genitals with both male and female characteristics, although male characteristics are more apparent. 

In men and young boys, the signs are small testes and a large penis, infertility, deep voice, early puberty, and well-defined muscles. 

After the initial 17-OH progesterone test, doctors have to conduct follow-up tests too to monitor your condition. If there's a change in the 17 hydroxyprogesterone levels, your doctor may change the treatment. 

Typically, there's no special preparation for the test. Your doctor may tell you not to eat and drink for a few hours before the test. If you take any medications, talk to your doctor. They may ask you to stop taking those, since some medicines can affect test results. 

Don't stop taking any prescription drugs on your own, though. Speak to your doctor first. 

If you're taking your child to be tested, it's best to put them in comfortable and loose clothes. This will make it easier for the technician to handle the child and perform the blood test

For newborns, healthcare professionals take the blood from the heel. They will clean the child's heel with alcohol. Then, they will use a small needle to poke it and collect some blood. They will later cover the site with a bandage. 

For adults, healthcare professionals take the blood sample from the vein in the arm. They'll use a small needle to poke your skin and draw a few drops of blood for a vial or test tube. 

The test does not pose any risks to your health. When pricked, you may feel a stinging sensation that goes away in a few minutes. Babies also feel a slight pinch when the technician pokes their heel. They may have a bruise on the site, but it will go away soon. 

The reference range for hydroxyprogesterone is measured in deciliters rather than milliliters because the former is a smaller unit and gives more accurate results. The reference range for the test is: 

  • Less than 630 nanograms per deciliter in newborns (sometimes, the amount may be above this limit in preterm babies)
  • Less than 110 nanograms per deciliter in prepubescent males (children who have not reached puberty yet)
  • Less than 220 nanograms per deciliter in adult males
  • Less than 100 nanograms per deciliter in prepubertal females
  • Less than 51 nanograms per deciliter in females after menopause

If the test results show a higher level of 17-OH progesterone, it means your child has CAH. If the child has moderately high levels of the hormone, they'll have a mild form of CAH, but if 17-OH progesterone levels are excessively high, your child will have a severe form of CAH. 

If you have any additional questions about the test or your child's health, speak to your doctor. They may advise you to opt for surgery to change the appearance of your child's genitals, depending on how severe the condition is.