Normally, a reproductive age woman will have regular menstrual cycle intervals every 28-30 x 4-5 days. Prior to the onset of the menstrual flow, premenstrual symptoms are common (including breast tenderness, headaches, abdominal bloating, and mood swings), which generally reflect the cycle’s normal changes in reproductive hormones. A history of regular menstrual cycle intervals with premenstrual symptoms is fairly strong clinical evidence that ovulation is occurring monthly.
Ovulation normally occurs about 14 days (2 weeks) prior to the onset of the next menstrual flow. In women with very regular menstrual cycle intervals, counting back 14 days from the expected next menstrual flow provides a rough estimate of the date of ovulation.
Ovulation tests include ovulation predictor kits that use test strips that are dipped in urine daily, which cause a chemical reaction that changes the color of the patient’s test result when LH is present. When a mature egg has been developed within the ovary, the body signals the ovary to get the egg ready for fertilization and to release the egg (ovulate) with a surge in the hormone LH. When the patient’s concentration of LH is great enough to suggest the LH surge (trigger to ovulate) then the patient’s test line on the test strip is often equal or darker than the test strip’s reference line. Since the egg normally will ovulate about 36 hours (one and a half days) after the onset of the LH surge, once the test strip is initially positive for the LH surge then ovulation can be expected within a day or so. These test strips are usually accurate for women, but sometimes they don’t seem to be reliable for (work effectively for) a particular woman.
Ultrasound examinations of the ovaries can determine the size of follicles (ovarian cysts that contain an egg) and serial ultrasound exams during the follicular phase of the menstrual cycle (egg development phase) can usually determine with high accuracy when a mature egg has developed. Once the egg is mature, ovulation can be triggered by administering the hormone hCG (human chorionic gonadotropin), which acts exactly like the LH surge to trigger ovulation. In this way, the timing of ovulation can generally be predicted accurately within a few hours.
Dr. Eric Daiter at The NJ Center for Fertility and Reproductive Medicine, LLC has extensive experience with ovulation problems and ovulation detection. He would be happy to help you. For an appointment to discuss your situation with Dr. Daiter, please call the office at 908 226 0250. Visit us on the web at http://www.drericdaitermd.com http://www.infertilitytutorials.com or http://www.ericdaiter.com