Generally speaking, late ovulation is ovulation that happens after the 21st day of a woman’s menstrual cycle. Not all women have exactly the same reproductive cycle; some ovulate earlier than others, for instance, and the length of menstrual bleeding can vary, too. Most medical practitioners follow a standard of “normal parameters,” and anything within these loose guidelines is usually considered healthy so long as the patient isn’t experiencing any other problems or issues. That said, ovulation — which is when an egg drops from an ovary and into the uterus for possible fertilization and implantation — typically happens by the 21st day. Anything past this is usually considered late. Late ovulation can be caused by a number of things, including the relatively benign, like stress, and the much more serious, including cysts and cancerous growths. It can impact fertility and can make it a lot more difficult for a woman to become pregnant.
Understanding What’s “Normal”
Normally, a woman will ovulate approximately two weeks into her menstrual cycle. Many doctors recommend that women who are concerned about their fertility try to create an ovulation chart before undergoing more detailed medical tests. Success in making this sort of chart depends almost entirely on a woman’s ability to pay attention to her body and to watch for signs and signals of what’s happening on the inside.
Increased basal body temperature, thinning of cervical mucus, and increased libido are some of the easiest to measure and track. Women who are very serious about knowing the precise moment of ovulation may also want to track their production of luteinizing hormones, though this usually requires a commercially prepared test. These are available in many pharmacies and chemists, and work by measuring protein levels in the urine in much the same way as a home pregnancy test does.
It’s important for women to keep in mind that the general two week guideline for ovulation assumes a regular 28 day menstrual cycle. Someone whose cycles tend to be longer or shorter than this may ovulate at a different time. Just because one woman ovulates later than a friend or family member doesn’t usually mean that she suffers from “late ovulation,” though. At least from a medical perspective, ovulation isn’t usually considered to be late so long as it happens somewhere between cycle day ten and cycle day 21. Only ovulation that occurs after cycle day 21 gets the “late” label.
Reasons Ovulation Might Be Late
The most common cause of late ovulation is a luteal phase defect indicated by poor follicle production, failure of the uterine lining to respond to normal levels of progesterone, or premature demise of the corpus luteum. Stress, illness, or excessive exercise can also be a cause for some women. This is most commonly the cause of sporadic lateness or the occasional missed egg; ovulation that is erratic or consistently late and difficult to chart may be a result of a more serious genetic defect or growth that is impeding ovarian function.
Role in Fertility
Late or missed ovulation isn’t always a problem for women, and many don’t even notice that it’s happening. It’s usually the most concerning when a woman is trying to become pregnant. First, the quality of a late egg is generally not as good as it would have been had it dropped on time. This isn’t necessarily problematic, but may be linked to various birth defects and problems with a pregnancy. Second, the lining of the uterus may be too old or too dense to support implantation at the time a late egg finally implants.
Practically speaking, a later-released egg also means fewer chances to try to conceive. To get pregnant, a woman should usually try to time intercourse during the four or five days leading up to ovulation. Sperm takes up to 72 hours to travel to its destination, so intercourse too late in the cycle may be less likely to result in fertilization. While pregnancy is still certainly possible, there’s usually a reduced window in these cases.
There are many misconceptions about the condition. For example, Polycystic Ovary Syndrome (PCOS), while the most common cause of no ovulation, is not usually tied to ovulation that is simply late. Skipping a month of ovulation is not abnormal, although it may be a cause for concern if it happens more than twice per year.