What Is Ovulation?

What Is Ovulation?

Ovulation is what happens when an egg, or ovum, is released from the ovaries. After ovulation, the egg then travels to the uterus via the fallopian tubes. If sperm meet up with the egg in time, conception may take place.

If you're new to trying to get pregnant or just want to know more about how the female reproductive system functions, it can be helpful to learn more about ovulation and its part in the process of conception. Below, we explain more about how ovulation works.

Why It's Important

During each menstrual cycle, reproductive hormones, including estrogen and progesterone, work together to stimulate the ovaries. In response to those hormones, follicles begin to grow in the ovaries. Inside each follicle is an immature egg, also known as an oocyte, which starts to mature.

Even though several oocytes will start developing at the beginning of each cycle, usually only one dominant egg will be released. If two eggs are released, you may conceive non-identical twins. Incidentally, while two or more eggs may occasionally be released in one cycle, this happens simultaneously, not at different times within one menstrual period.

Ovulation and Conception

While the ovaries are preparing to release an egg, the uterine lining (endometrium) gets ready to receive a fertilized egg, or embryo, by thickening. The body's hormones lead to the thickening and changing of the endometrium.

You might assume that the eggs in the ovary develop from the first stage to ovulation in a month's time, but that's untrue. Individual oocytes develop over several months. They go through various stages until they are either ready to ovulate or stop growing and remain dormant. Hormones, chromosomal issues, structural defects, or chance prevent the other oocytes from fully developing.

Most of the eggs in a woman's ovaries never mature to ovulation. When a woman begins puberty, the ovaries house approximately 300,000 eggs. Despite this apparent storehouse of eggs, a woman only ovulates around 300 ova over their lifetime.

There is also a misconception that each ovary takes a turn ovulating every other month. For example, one month the right ovary ovulates. Then, the next month, the left ovary ovulates. In fact, ovulation occurs on whichever side has the most mature ova or ovum in that month. In some women, one ovary may ovulate significantly more often than the other.

When Will I Ovulate?

Ovulation usually occurs between day 11 and day 21 of the menstrual cycle. Each woman ovulates on their own schedule. You've probably heard that ovulation occurs on Day 14 of your cycle, but that's just an average benchmark. In fact, even women with 28-day menstrual cycles don't always ovulate on Day 14. One study found that fewer than 10% of women with 28-day cycles were ovulating on Day 14.

Usually, when a woman says they're ovulating, they're referring to the especially fertile period of two to three days that precede ovulation. If we assume ovulation occurs somewhere between day 11 and day 21, this extra fertile period can occur as early as day 9 of the menstrual cycle and as late as day 22. That's a wide range! This is why most women who want to conceive will track ovulation and fertility signs.

What to Look For

Most women experience certain symptoms around the time of ovulation. Some symptoms may appear several days before ovulation, while others won't happen until the day before or day of ovulation. These symptoms include changes in sexual desire, an increase in cervical mucus, and sometimes crampy pain.

How Do I Know I'm Ovulating?
Verywell / Laura Porter

One way to detect ovulation is by measuring basal body temperature, or your temperature when you're completely at rest. By taking your temperature first thing every morning, before you get out of bed, and charting the results, you can look for the telltale rise that signals ovulation.

Another option is to use ovulation test kits. These tests work a lot like pregnancy tests, in that they detect a particular hormone in your urine. When you get a positive result on an ovulation test, you're approaching ovulation, and you should have sex.

Be aware that not all ovulation kits are highly accurate and some may be difficult to interpret. In fact, studies show that the reliability of these products ranges from 19% to 99% and that mistiming sex is a key contributing factor in some couples' infertility challenges. So, be sure to vet the accuracy of any test you use.

The most accurate way to determine ovulation is via a transvaginal ultrasound with an OB/GYN or at a fertility clinic.

Tips for Conception

Conception requires at least one ovum and one sperm. Semen can live up to five days in the female reproductive tract. So, if a couple has sex on Monday, there will still be live, viable sperm hanging out in the woman's fallopian tubes on Thursday.

The human ovum, however, lives for just 24 hours. Plus, it must be fertilized within the first 12 hours after ovulation for conception to occur. This is why you need to have sex before you ovulate. If you want to get pregnant, sex before ovulation will ensure there are sperm cells waiting to greet the ovulated egg. There's no need to have sex at the very moment of ovulation, but that works, too.

Optimal Timing for Sex

While knowing when you are ovulating can help you time sex for your most fertile days, it's not required. If you have sex three to four times a week, you're bound to have sex around your ovulation period. Ideally, have sex every other day during your fertile window so that the sperm has time to regenerate and mature between copulation.

When Are You Pregnant?

When a sperm cell fertilizes the egg, conception takes place. However, you are not technically pregnant at this moment. The egg must implant for pregnancy to start.

To be considered pregnant, the fertilized egg must embed itself into the endometrium. This happens 7 to 10 days after fertilization.

Additionally, a woman who is going through IVF isn't officially pregnant after embryo transfer. Even though the embryo is now inside the uterus, they're not "pregnant" unless the embryo implants itself into the endometrium.

Potential Challenges

If you don't experience ovulation symptoms at any time during your cycle, or if you have irregular periods, you may not be ovulating every month—or at all. Anovulation is when a woman does not ovulate. This condition is a possible sign and common cause of infertility. Other symptoms of anovulation are extremely short or long periods or a complete absence of menstruation.

High levels of stress, hormonal abnormalities, extreme weight loss, malnutrition, obesity, thyroid dysfunction, and polycystic ovary syndrome (PCOS) are some typical causes of anovulation. Treatments include lifestyle changes, such as weight loss or gain, and medicines like fertility drugs to stimulate ovulation.

A Word From Verywell

While couples are often told to try on their own to conceive for at least six months to a year before seeking fertility treatment, if you have symptoms of a problem, that timeline doesn't apply. Talk to your doctor sooner rather than later. Earlier diagnosis can improve your odds of successful treatment.

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