A Ovulation test done at home can measure Luteinizing Hormone (LH) in your urine. This helps detect the LH surge that happens in the middle of your menstrual cycle, about 1-1½ days before ovulation. Some tests also measure another hormone -- estrone-3-glucuronide (E3G).

What is LH?

Luteinizing Hormone (LH) is a hormone produced by your pituitary gland. Your body always makes a small amount of LH, but just before you ovulate, you make much more LH. This test can detect this LH surge, which usually happens 1-1½ days before you ovulate.

What is E3G?

E3G is produced when estrogen breaks down in your body. It accumulates in your urine around the time of ovulation and causes your cervical mucus to become thin and slippery. Sperm may swim more easily in your thin and slippery cervical mucus, increasing your chances of getting pregnant.

What type of test is this?

This is a qualitative test -- you find out whether or not you have elevated LH or E3G levels, not if you will definitely become pregnant.

Why should you do this test?

You should do this test if you want to know when you expect to ovulate and be in the most fertile part of your menstrual cycle. This test can be used to help you plan to become pregnant. You should not use this test to help prevent pregnancy, because it is not reliable for that purpose.

How accurate is this test?

How well this test will predict your fertile period depends on how well you follow the instructions. These tests can detect LH and E3G reliably about 9 times out of 10, but you must do the test carefully.

How do you do this test?

You add a few drops of your urine to the test, hold the tip of the test in your urine stream, or dip the test in a cup of your urine. You either read the test by looking for colored lines on the test or you put the test device into a monitor. You can get results in about 5 minutes. The details of what the color looks like, or how to use the monitor varies among the different brands.

Most kits come with multiple tests to allow you to take measurements over several days. This can help you find your most fertile period, the time during your cycle when you can expect to ovulate based on your hormone levels. Follow the instructions carefully to get good results. You will need to start your testing at the proper time during your cycle, otherwise the test will be unreliable, and you will not find your hormonal surges or your fertile period.

Is this test similar to the one my doctor uses?

The fertility tests your doctor uses are automated, and they may give more consistent results. Your doctor may use other tests that are not yet available for home use (i.e., blood and urine laboratory tests) and information about your history to get a better view of your fertility status.

Ovulation test kits allow you to predict your most fertile time of the month and are important tools for women who are trying to conceive through natural means or through artificial insemination.

Ovulation tests work by detecting the presence of and levels of luteinizing hormone, which experiences a brief surge just before a woman ovulates. Since ovulation is the most fertile moment of the month, this allows the woman and her partner to time her attempts at coitus or artificial insemination accordingly for a greater chance at fertilization.

Ovulation tests results are often differently from ordinary pregnancy test kits. A positive result, which is indicative of high levels of LH, often shows as a band with a darker or equal color and intensity than the control band. In most pregnancy tests, two bands indicate a positive, while one narrow band is often a negative. A negative result in ovulation kits shows as a band of lighter color and intensity than the control band.

Furthermore, unlike pregnancy tests, which need to be taken early in the morning, ovulation kits have to be used at around 2 pm in the afternoon, since L H is synthesized in the body in the morning and only appears later in the afternoon. Women are advised to take the test at the same time each day and to reduce water intake two hours prior to the test. This is because too much water can dilute the sample and lead to erroneous results.

Ovulation or fertility tests are important are reliable tools for women who are trying to get pregnant either by artificial or natural means. Ovulation tests detect the presence of luteinizing hormone and follicle stimulating hormone which are elevated during the womans most fertile moments. Being able to determine the womans most fertile periods in the month can help the couple time coitus or fertility treatments accordingly to have a greater chance for successful fertilization.

One common misconception about ovulation tests is that they function the same way as pregnancy kits do. However, an ovulation test kit looks and is read differently than a pregnancy kit. In some ovulation kits a positive result which indicates high levels of luteinizing hormone is often represented as a darker band with a greater intensity than the control band. In typical pregnancy kits, on the other hand, a positive result shows as two bands and a single band for a negative result. A negative result in an ovulation test shows as a lighter, less intensely-colored band compared to that of the control.

Another difference is the timing of the tests. Pregnancy tests are best taken during the morning while ovulation tests need to be taken in the early afternoon, when leuteinizing hormone is most likely to appear. The timing should be the same each day and women are also advised to reduce water intake two hours before taking the test, since too much fluids can give a diluted sample which can lead to erroneous results.