Ovulation refers to the release of an egg from the ovarian follicle. This happens once a month. Once released, the egg can then be fertilized over the next 12-24 hours before it begins to disintegrate. If the egg is fertilized it travels down the fallopian tube into the uterus where it can implant, and a woman becomes pregnant. The unfertilized egg disintegrates and is absorbed.
Sometimes, during ovulation or shortly before (pre-ovulation), a woman may experience some bleeding, the so-called "ovulation bleeding" or "pre-ovulation bleeding". Ovulation bleeding is different from the regular menstrual flow:
- It is lighter than menstrual flow.
- It typically will last only for one to two days.
- It tends to be pink and less red in color.
A variety of factors can cause ovulation bleeding. For most women who experience ovulation bleeding, the cause is not clear. It may be related to the emergence of the follicles. Hormones prompt ovaries to produce around 20 follicles that contain an immature egg, and out of this only one follicle matures. It is during this process of maturing and bursting out from the follicle that pain or bleeding occurs. Regular ovulation bleeding that is severe or that lasts longer than a couple of days is not normal and should be evaluated by a doctor.
Bleeding episodes that are very irregular or which are 2 weeks apart suggest that there may be irregular or absence of ovulation altogether. Other causes of irregular bleeding include irritation to the cervix, polyps in the cervix, or polyps in the uterus.
If you do have irregular bleeding, a physical examination of the uterus to help determine the cause of abnormal bleeding. An ultrasound examination or a diagnostic hysteroscopy can help detect sub-mucous fibroids, polyps, and other problems. During a diagnostic hysteroscopy, it is possible to remove polyps for examination and take a sample of the uterus lining.
Bleeding during mid-cycle does not indicate menses. If ovulation bleeding is severe or long-lasting, and/or are accompanied by pain or acute discomfort, it may be a sign of a larger problem. However, if the bleeding is extremely mild and short, and is not accompanied by pain and discomfort, it may be completely normal.