Ovulation predictor kits test for the presence of luteinizing hormone (LH) in the urine. The pituitary gland increases LH production 12 to 16 days before menstruation begins. This “LH surge” causes an ovarian follicle to rupture and releases a mature egg in 1 to 1.5 days (24 to 40 hours). The onset of the LH surge (and therefore ovulation) can be estimated by using the ovulation predictor tests for several days. An egg survives for 12 to 24 hours after ovulation. If the egg and sperm are not united shortly after ovulation, conception will not occur.
It is possible the LH surge and ovulation will not occur during every menstrual cycle. Onset of menstrual bleeding does not always mean ovulation has occurred.
To aid in planning pregnancy; to determine fertile time of menstrual cycle.
Menopause: Women entering menopause may have high LH levels during their entire menstrual cycle.
Day for beginning testing is determined by the approximate length of the menstrual cycle, the first day being the onset of bleeding (even spotting), the last being the day before bleeding onset. Test kits vary regarding the date to begin testing. Follow manufacturers’ instructions carefully.
Specimen collection and handling: Collect urine in the urine cup from the kit or in a clean, dry container. If testing cannot be done in 3 to 4 hours after collecting the urine specimen, cover and refrigerate immediately. Let it return to room temperature before testing. Do not freeze specimen. For best results, do the test the same day as the urine was collected.
Time: Allow enough time to complete the test.
Tell your doctor or pharmacist if you are taking or if you are planning to take any over-the-counter or prescription medications or dietary supplements while testing for LH surge (ovulation). The following drugs and drug classes may interact with the test to cause questionable results:
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