An ovulation monitor, sometimes called a fertility monitor, is a product that helps a woman identify her days of highest fertility during the month. In order to understand how an ovulation monitor works, it is important to understand the hormonal changes that occur during a woman's menstrual cycle. Three hormones, estradiol, lutenizing hormone (LH), and progesterone, control the menstrual cycle. Estradiol slowly increases before ovulation, followed by a brief burst of LH just prior to ovulation. Following ovulation, progesterone increases in order to prepare the body for pregnancy, but if fertilization has not occurred, progesterone levels drop off, and a woman has her period.
A woman who is trying to become pregnant may use an ovulation monitor to determine her time of peak fertility in a given month. Ovulation occurs once a month, and the egg survives for about 24 hours. In order to become pregnant, a woman should have sex on or before the day she ovulates. Her partner's sperm can survive in her body for several days, so having sex up to five days before ovulation could result in conception.
A simple ovulation test detects the LH surge that occurs just before ovulation. This test involves holding a testing stick in the urine stream so that hormones in the urine can be detected, similar to a pregnancy test. An ovulation monitor detects not only the LH surge, but also the rise in estradiol that occurs prior to the LH surge. By detecting the estrogen rise, a woman will know she is going to ovulate in a few days, and by having sex during this period, she increases her chances of becoming pregnant.
Using a simple ovulation test, it is up to the woman to determine when she is likely to ovulate. A few days before she believes she will ovulate, she tests her urine each morning. An ovulation monitor provides the additional function of telling a woman when she should test her urine. The kit comes with a small hand held device that is activated on the first day of a woman's period. It can store information about the length of a woman's menstrual cycle and tell a woman whether or not she should test her urine each day.
