Ovulation is the point in the menstrual cycle in which a single ovum, or egg, is discharged from the ovarian follicle into the Fallopian tube. This phase of the cycle typically occurs between day 11 and day 21, and is when a female is at her most fertile. Unlike the menstrual period, ovulation is typically not associated with bleeding. However, through years of collecting medical data, researchers have discovered that 10 to 30 percent of women will experience mid-cycle bleeding during their childbearing years. For many of these women, this bleeding will occur during the ovulatory phase.
The Causes of Ovulation Spotting
It is considered normal for light bleeding to occur before, during and after ovulation. Ovulation spotting is believed to be triggered by the release of the egg from the follicle. During ovulation, the ovaries produce approximately 20 egg-containing follicles, one of which will cultivate an egg to maturity. Once the egg has fully matured, it will burst from the follicle and travel down the fallopian tube. This bursting action can cause bleeding in the ovary, which will be released along with the egg. The sudden drop in estrogen that occurs immediately before the discharge of the egg may also trigger spotting during ovulation. Another common cause of mid-cycle bleeding is hormonal birth control. If you have recently begun taking birth control or take your birth control irregularly, you may experience bleeding until your body adjusts to the hormones.
Determining Normal versus Abnormal Ovulation Spotting
Normal ovulation spotting is very different than menstrual bleeding. Unlike menstrual blood that is often red, this blood usually appears pink or brownish in color. Bleeding should be light and should only persist for a few days. While not every woman experiences these symptoms, mild bleeding is not cause for alarm and should not affect your fertility. It is also normal to experience ovulation bleeding periodically. Just because you notice spotting one month does not mean that you will experience bleeding during every ovulation phase.
When Ovulation Bleeding Becomes a Cause for Concern
Unfortunately, there are times when ovulation bleeding can be a sign of a larger problem. It is not normal to experience ovulation bleeding that is heavy, long lasting or accompanied by pain. Heavy or painful bleeding during ovulation can sometimes be caused by abnormal thyroid function, certain infections, uterine fibroids, uterine polyps or a hormonal imbalance. It is also possible for endometrial cancer to cause bleeding around ovulation. To avoid future health problems, you should discuss any serious changes in your cycle, including severe bleeding during ovulation, with your physician.
Human Reproduction Update; Livingstone, M
Mechanisms of abnormal uterine bleeding
2002; Volume:8; No: 1; Pages: 60-67
American Pregnancy Association
American Family Physician
Abnormal Uterine Bleeding