Lesson 14 - Guide to Ovulation

Lesson Objectives:

  • Learn about ovulation and what role it plays in fertility
  • Know how fertility charting can be used to pinpoint ovulatio

Major Points in this Lesson:

  • Ovulation is the release of a mature egg cell, or ovum, from an ovarian follicle.
  • After ovulation, the lifespan of the egg is typically between 12 and 24 hours, but can be as few as six hours.
  • When the ovum is fertilized by a male’s sperm during this short time frame, conception occurs.
  • Engaging in intercourse prior to ovulation may result in conception as the sperm is able to survive in the female reproductive tract for several days prior to ovulation.
  • Determining the date of ovulation is a major concern when charting your fertility.
  • Charting your fertility signs can help you detect ovulation as the hormone progesterone, which is released after ovulation, causes your resting body temperature to rise and remain elevated throughout the luteal phase.
  • The ability to detect ovulation can help you determine if intercourse is well-timed for conception, if you can cease baby-making intercourse, the average length of your luteal phase, and when you could possibly expect a positive pregnancy test.

Fertility charting involves identifying ovulation and using this information to make the calculations necessary to establish your fertility status. By using your observations of when and if you ovulated, you can make important decisions, such as deciding to take a break from baby-making intercourse. You can also better time your intercourse to increase your odds of conception. Fertility charting may also tell you the most reliable time to take a pregnancy test or when you can expect your next period.

A Closer Look at Ovulation

Ovulation is described as the release of a mature egg cell (ovum) from an ovarian follicle. During a menstrual cycle, multiple ovarian follicles mature with help from pituitary hormones. However, only one of these follicles will fully develop. As the other follicles diminish, the dominant follicle produces an egg to be fertilized. The follicle also secretes the hormone estrogen. After a peak in estrogen, the body experiences a surge of luteinizing hormone (LH), which triggers the release of the mature egg from the follicle. This process is ovulation.

What Happens After Ovulation

After its release, the mature egg travels through a fallopian tube towards the uterus. This is where fertilization may occur. After the release of the egg, the dominant follicle (now called the corpus luteum) begins to secrete progesterone (a heat-inducing hormone).

Following ovulation, the lifespan of the egg is just 12 to 24 hours, sometimes less. For conception to occur, the egg must be fertilized within this time frame. If this time frame passes without fertilization, the egg will degenerate and lose its ability to be fertilized. While the time frame may seem brief, male sperm is able to survive in the reproductive tract for several days. This means that the days leading up to ovulation are also considered fertile days.

Phases of the Menstrual Cycle

Ovulation defines the phases of a woman’s menstrual cycle. The follicle phase occurs before ovulation and involves the development of the ovarian follicles. The luteal phase comes next. While the length of the follicle phase can vary from month to month, the luteal phase is fairly consistent, lasting an average of 10 to 16 days. If your cycles are irregular, it may be due to ovulating sooner or later than normal. By charting when ovulation occurs, you can better time intercourse and determine your average luteal phase length. When you know your luteal phase, you can better determine when to expect your next period or a positive pregnancy test.

Pinpointing When Ovulation Will Take Place

On average, ovulation takes place approximately two weeks prior to the start of your period. However, it can vary from 10 to 16 days depending on your unique luteal phase. Ovulation can be expected between cycle days 13 and 15 for women with an average 28 day cycle. For these women, ovulation will typically occur around day 14. However, it’s common to see some irregularities in your menstrual cycle from time to time.

Menstrual cycles can span from 21 to 35 days on average. Some women may have longer or shorter cycles.  As there is no one-size-fits-all, it’s important to watch for your fertility signs to better pinpoint ovulation. 

How to Detect Ovulation

Charting your fertility signs can help you better detect your ovulation date and your peak fertility. As you near ovulation, your body may produce signs that let you know that ovulation will soon occur. For example, stretchy “egg white” cervical fluid and a soft, high, and open cervix may tell you that your estrogen levels are high and that ovulation will soon occur.

There are numerous commercial devices on the market that can help you detect ovulation, such as fertility monitors and ovulation prediction kits (OPKs). These devices work by measuring the presence of the hormone estrogen or luteinizing hormone (LH) in your urine. You can also target ovulation by charting your basal body temperature using an in-ear thermometer. When taking your BBT, you’ll likely notice a rise in your basal body temperature after ovulation due to the hormone progesterone.