Ovulation kits, or ovulation predictor kits (OPKs), are tests women use to predict when they will ovulate. Females ovulate when the ovary, a female reproductive organ, releases an egg into the fallopian tubes. Typically, this occurs roughly two weeks into the average 28-day menstrual cycle. Many women, however, have very irregular cycles and do not fit this pattern. The days surrounding ovulation are the days in which women are fertile, or capable of becoming pregnant. For this reason, ovulation kits are often used by women wishing to become pregnant and sometimes by those wishing to avoid pregnancy.
Ovulation kits estimate the time of a woman's ovulation by monitoring the concentration of luteinizing hormone (LH) in her urine. LH is always present in the urine, but it increases in the 24 to 48 hours prior to ovulation. This increase causes an egg to drop from one of the ovaries, known as ovulation. If a woman is seeking to become pregnant, it is best to have sexual intercourse the day she tests positive for elevated LH, and for two days following the positive results.
To use an ovulation kit, the female should either urinate directly on the test stick or urinate in a sterile cup and then submerge the end of the test stick in the urine for five to twenty seconds. This should be done at the same time every day. It is recommended that the kit be used some time between 12:00 - 8:00 pm. The kit then reads the LH level in the urine which lets the woman know how high or low her chances of conception are.
Ovulation kits have been proven to be very accurate and can teach a woman about her cycle. There are different brands of ovulation kits and each one displays results differently. Some will show two lines, one being darker than the other depending on the LH level. Others are digital and will show more or less bars depending on the LH level.
A woman can also monitor her basal body temperature (BBT) to raise fertility awareness, but it is not as effective as using ovulation kits. BBT usually increases one-half to one degree Fahrenheit (-17.2 to -17.5 degrees celsius) during ovulation, but ovulation kits will test positive right before ovulation. By the time the BBT rises, the woman may have already missed her chance to conceive, whereas an ovulation kit allows more time to prepare for the egg to drop.
Saliva ovulation testers show a woman's fertility through her saliva. The kit contains a small microscope in which the woman may observe her dried saliva and what is referred to as the "ferning effect". The saliva will resemble fern leaves if the woman is fertile. This method is proven to be successful, but it is not as accurate as measuring LH levels.
A woman's age affects her chances of conception. Statistics show that women between the ages of 20 and 25 have the best chances of getting pregnant. After 25, the chances start to decrease and after 35, they drop drastically. This means that although the test might give an older female the green light, it might take a number of cycles for her to actually conceive.