Definition

A progesterone test measures the levels of the hormone progesterone in the body. This hormone is produced by the adrenal glands and the corpus luteum, a structure in the ovaries that forms after ovulation.

Progesterone is essential for pregnancy, as it prepares the uterus for implantation. Elevated progesterone levels during pregnancy help sustain the pregnancy and inhibit breast milk production. After childbirth, progesterone levels drop, triggering breast milk production.

In addition to its role in pregnancy, progesterone regulates the menstrual cycle. Levels of this hormone increase during ovulation, preparing the body for ovulation or potential fertilization.

If fertilization does not occur, progesterone levels will decrease. Conversely, if pregnancy occurs, progesterone levels can increase up to tenfold compared to normal levels.

The progesterone test is a valuable tool for identifying fertility issues in women, diagnosing pregnancy-related complications, and assessing adrenal gland problems associated with elevated progesterone levels.

Indications

A progesterone test is performed under the following circumstances:

• To identify the cause of infertility in women.
• To evaluate the effectiveness of fertility treatments.
• To determine the cause of miscarriage.
• To assess the risk of miscarriage during pregnancy.
• To diagnose ectopic pregnancy.
• To monitor high-risk pregnancies.

Doctors may also recommend the test in cases of:

• Difficulty conceiving.
• Undergoing fertility treatments.
• Unexplained bleeding outside of pregnancy.
• Pregnant individuals with:
  • Progesterone therapy to prevent miscarriage.
  • High risk of miscarriage or pregnancy complications.
  • Signs of miscarriage or ectopic pregnancy.

Contraindications

There are no known contraindications for the progesterone test. It is generally considered safe for individuals of all ages.

Preparation Prior to Test

The progesterone test does not require any special preparation, and fasting is not necessary. However, consulting your doctor beforehand is advisable since certain factors may affect laboratory results and lead to inaccurate findings.

You should provide your doctor with information about the start and end dates of your most recent menstrual cycle and details about any medications or supplements you are taking. Your doctor may recommend discontinuing certain medications prior to the test to ensure accurate results.

Test Procedure

The progesterone test typically requires a blood serum sample of 0.25–0.5 mL. The sample is collected from a vein and stored in a special tube. During the collection process, laboratory staff will use personal protective equipment (PPE) for safety.

Before drawing blood, the technician will place an elastic band around the arm to make the veins more visible and clean the puncture site with antiseptic gauze. Blood is commonly drawn from the crease of the elbow. Once the blood is collected into the special tube, the elastic band is removed, and the puncture site is cleaned and pressed with antiseptic gauze.

The procedure is quick, typically taking only a few minutes. The blood sample is then analyzed in the laboratory using specialized equipment, with results available within a few hours.

Normal and Abnormal Values

The normal range for progesterone levels depends on factors such as gender, age, menstrual cycle phase, and pregnancy status.

In women with normal menstrual cycle, progesterone levels in the blood will be low at the beginning of the cycle and peak a few days after ovulation. Progesterone levels will subsequently decrease unless pregnancy occurs.

The normal range of progesterone hormone in the blood is:

• Before puberty: 0.1–0.3 ng/mL
• Follicular phase of menstrual cycle: 0.1–0.7 ng/mL
• Luteal phase of menstrual cycle: 2–25 ng/mL
• First trimester of pregnancy: 11–44 ng/mL
• Second trimester of pregnancy: 25–83 ng/mL
• Third trimester of pregnancy: 58–214 ng/mL
• Post-menopausal women: < 0.2 ng/mL

A progesterone test result is considered low if it falls below these ranges and high if it exceeds the normal range.

Results and Recommendations (Follow-up Tests)

Low

If the test results show low values in pregnant women, they may be experiencing:

• Ectopic pregnancy.
• Miscarriage or high risk of miscarriage.
• Preeclampsia.
• Intrauterine fetal death (IUFD).

If the test results show low values in non-pregnant women, they may be experiencing:

• Amenorrhea.
• Ovarian disorders or ovulation failure.

Normal

A normal progesterone level indicates a healthy hormonal balance with no signs of ovarian or adrenal gland issues, assuming no concerning symptoms or clinical signs.

Maintaining a healthy lifestyle is recommended to prevent conditions associated with abnormal progesterone levels, such as miscarriage or cancer.

High

If the test results show high values in pregnant women, they may be experiencing:

• Pregnancy with a single fetus, twins, or more.
• Molar pregnancy (an abnormal form of pregnancy).

If the test results show high values in non-pregnant women, they may be experiencing:

• Ovarian cysts.
• Ovarian cancer.
• Adrenal cancer.
• Adrenal gland disorders

Consult the Right Doctor

Adults with abnormal progesterone test results should consult a general practitioner for further diagnosis and therapy. An obstetrician may be needed for specific discussions related to progesterone hormone concerns, particularly during pregnancy. For pediatric patients, any abnormal test results should be reviewed with a pediatrician to determine appropriate next steps.

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