Progesterone

The Progesterone test measures the level of the hormone progesterone in the blood. Progesterone is primarily produced in the ovaries after ovulation and plays a vital role in regulating the menstrual cycle, supporting pregnancy, and maintaining uterine lining. In men, progesterone is produced in small amounts and supports sperm development and other functions.

1. What Is Progesterone?

• Progesterone is a steroid hormone secreted mainly by the corpus luteum in the ovary after ovulation.

• It helps prepare the uterus for implantation of a fertilized egg and supports early pregnancy.

• In men, it is produced in smaller amounts by the adrenal glands and testes.

2. Why Is the Progesterone Test Performed?

This test is used to:

• Confirm ovulation in women trying to conceive.

• Monitor the health of a pregnancy (especially in early stages).

• Diagnose causes of infertility, abnormal uterine bleeding, or menstrual irregularities.

• Evaluate progesterone-producing tumors or adrenal gland disorders.

3. Progesterone Reference Ranges (Women)

• Follicular phase: < 1 ng/mL

• Luteal phase: 5 – 20 ng/mL

• First trimester pregnancy: 11 – 44 ng/mL

• Postmenopausal: < 1 ng/mL

• Men: < 1 ng/mL (varies by lab)

4. Interpreting Progesterone Results

🔹 High Progesterone:

• Indicates recent ovulation or pregnancy.

• May also be due to ovarian cysts, molar pregnancy, or certain hormone therapies.

🔹 Low Progesterone:

• Suggests lack of ovulation (anovulation), luteal phase deficiency, or risk of miscarriage.

• In men, low levels are rarely clinically significant unless related to adrenal or testicular dysfunction.

5. What Can Affect Progesterone Levels?

• Timing of the menstrual cycle (levels fluctuate significantly).

• Pregnancy status and trimester.

• Hormonal medications (e.g., birth control or fertility treatments).

• Medical conditions affecting ovulation or hormone production.

6. How Is the Test Performed?

• A blood sample is taken from a vein.

• Timing is important — usually done about 7 days after ovulation (day 21 of a 28-day cycle).

7. When to See a Doctor

🚨 Contact your healthcare provider if you:

• Are trying to conceive and want to confirm ovulation.

• Experience irregular periods, infertility, or abnormal bleeding.

• Have symptoms of low progesterone during pregnancy (e.g., spotting, cramping).

🔹 Key Takeaways

✅ Progesterone is essential for ovulation, fertility, and pregnancy maintenance.

✅ Low levels may affect the ability to conceive or carry a pregnancy.

✅ Accurate testing requires proper cycle timing and interpretation based on context.