Pregnanediol

Definition

This is a test that measures the amount of pregnanediol in urine.

How the test is performed

A 24-hour urine sample is needed. The health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test.

• On day 1, urinate into the toilet upon arising in the morning.
• Collect all subsequent urine (in a special container) for the next 24 hours.
• On day 2, urinate into the container in the morning upon arising.
• Cap the container. Keep it in the refrigerator or a cool place during the collection period. Label the container with your name, the date, the time of completion, and return it as instructed.

How to prepare for the test

The health care provider may advise you to discontinue drugs that can affect the test. (See "Special Considerations".)

How the test will feel

The test involves only normal urination, and there is no discomfort.

Why the test is performed

Before progesterone blood tests were available, this test was used to document problems of pregnancy and to evaluate suspected problems with the ovaries or adrenal cortex. Currently there is little use for the test except in home ovulation predictor kits.

Pregnanediol is an inactive product of progesterone metabolism. Urinary pregnanediol is an indirect measure of progesterone levels in the body. In women, progesterone is produced mainly by the corpus luteum following ovulation. Some progesterone is also produced by the adrenal cortex.

During pregnancy, most progesterone is produced by the placenta. The main function of progesterone is probably to increase the secretory phase of endometrial development, during which the uterus is prepared for possible implantation by a fertilized egg. After fertilization, progesterone is necessary for the development and maintenance of the placenta.

Normal Values

• male: 0.1 to 0.7 mg/24-hours
• female:
  • follicular phase: < 1.0 mg/24-hours
  • luteal phase: 2 to 5 mg/24-hours
  • pregnancy at 20 weeks: 40 mg/24-hours
  • pregnancy at 30 weeks: 80 mg/24-hours
  • pregnancy at 40 weeks: 100 mg/24-hours
  • postmenopausal: 0.2 to 1.0 mg/24-hours

Note: mg/24-hours = milligrams per 24 hours

What abnormal results mean

Higher-than-normal levels may indicate:

• adrenocortical hyperplasia
• arrhenoblastoma of ovary
• choriocarcinoma of ovary
• hyperadrenocorticism
• ovarian cyst

Lower-than-normal levels may indicate:

• amenorrhea
• fetal death
• ovarian cancer
• decreased ovarian function
• preeclampsia
• threatened abortion
• toxemia of pregnancy

What the risks are

There are no risks.

Special considerations

• ACTH may increase test measurements.
• Birth control pills or progesterone may decrease test measurements.

Illustrations

Female urinary tract

Male urinary tract

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