Health Conditions

Most often, a woman who may be infertile is evaluated to find out if her ovaries are working properly. Ovulation (the release of a mature egg from one of her ovaries) typically occurs in the middle of a regular 28-day menstrual cycle. The woman's egg is available for fertilization for 12 to 24 hours after ovulation and sperm can retain their ability to fertilize the mature egg for 24 to 48 hours. Therefore, if the time of ovulation can be determined, sexual intercourse can be planned to have the best chance of successful fertilization.

The most common methods for determining if or when ovulation occurs include:

Charting of Basal Body Temperature (BBT)
Since basal body temperature (the lowest body temperature of the day) varies throughout the menstrual cycle, a woman can keep track of her BBT to estimate when ovulation occurs. BBT is usually measured at about the same time every morning before the woman gets out of bed. Normally lower than average body temperature, which is 98.6oF, BBT is lowest about 2 days before ovulation and then goes up slightly ?about one-half a degree ? during ovulation. Women measuring BBT usually use special thermometers that make reading the small changes in temperature easier. After tracking BBT for several months, the couple may be able to identify an approximate ovulation period (usually within a 2 to 3 day time frame).

Charts to track BBT can be obtained from a doctor or downloaded from Web sites such as: http://www.4woman.gov/Pregnancy/bbt-chart-blank.pdf. For detailed instructions on how to use a BBT chart, please see http://www.fertilityplus.org/faq/bbt/bbtfaq.html

Ovulation Testing Kits
Several brands of ovulation testing kits are available without a prescription for use at home. Ovulation tests detect the presence of a chemical known as luteinizing hormone (LH) in the woman?s urine. During the menstrual cycle, a large increase in LH triggers ovulation. Identifying the LH surge can help pinpoint the time of ovulation, which generally can be expected to occur within 36 hours after LH enters the urine. Most kits contain a series of 5 to 9 daily urine tests that take between a few minutes and an hour to perform each morning, depending on the kit.

Progesterone Levels
Measuring blood levels of progesterone is another method of determining the time of ovulation. Normally, after ovulation occurs, progesterone levels are relatively high because progesterone helps prepare the uterus to receive and implant the fertilized egg. Measuring the amount of progesterone in the blood on day 21 of a 28-day menstrual cycle (about a week after ovulation should have occurred) helps doctors tell if ovulation did take place. Checking progesterone levels is a test that requires doctor?s office or clinic visits.

Ultrasound Monitoring Often used to determine when fertility drugs should be taken, ultrasounds also can determine whether or not a woman is ovulating. Ultrasounds are usually done on a hospital outpatient basis. Using high frequency sound waves, ultrasound testing shows the shape of various organs and tissues in the body. For infertility testing, ultrasound assesses the thickness of the uterine lining and the condition of the ovaries. Specifically, an ultrasound image can show the development of follicles, the structures that contain developing eggs inside the ovaries.

Endometrial Biopsy
An endometrial biopsy involves examining a tissue sample from the uterine lining under a microscope. About 2 or 3 days before the menstrual period, a sample of the endometrium is collected in a doctor?s office or infertility clinic. Samples may be obtained in several ways that include scraping the uterus or using a suction device. If ovulation has occurred, the sample of tissue is likely to show the effects of progesterone, a hormone that helps prepare the uterus support a fertilized egg. Because an endometrial biopsy may be uncomfortable ? especially for women in their late thirties or forties ? and because it is a more invasive procedure, it is usually reserved until other ovulation tests have been inconclusive.

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Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.