Getting pregnant

Ovulation & the signs of fertility

At and around ovulation is the most fertile time of the month, and therefore, the best time to have intercourse if you’re trying to get pregnant.

The Woman

Knowing when you ovulate: Most women ovulate two weeks, or 14 days before their next menstrual period, so you should count backwards from the anticipated start of your next period. To figure it out, follow these easy steps:

1. Take the number of days in your usual cycle (from the beginning of one period to the beginning of the next). For example, most women have cycles that last 28 days.
2. Then subtract 14. So, 28-14=14. You would ovulation around day 14 in this case.

A woman with a 32 day cycle, would ovulate around day 18 (32-14=18). Because the sperm live longer than the egg does, (sperm live 48-72 hours after ejaculation), it’s best to have intercourse before ovulation rather than afterwards. Following our example, a woman who ovulates on day 14 would have a good chance of getting pregnant if she has intercourse on either day 13 or 14.

For women with irregular cycles, one way to decide on the potential fertile period is by taking the shortest cycle and subtracting 16, then taking the longest cycle and subtracting 12. This would give the fertile time and allow for even more fluctuation in cycle length than usual. For example, the fertile period for a woman whose cycles vary from 27 to 33 days should be sometime between day 11 (27-16=11) and day 21 (33-12=21).

Women with irregular cycles may also want to consider using other methods to determine ovulation. Those other methods include looking for cervical mucus changes, measuring your basal body temperature, and using ovulation predictor kits.

Looking for cervical mucus changes

During the menstrual cycle, mucus is discharged from the cervix into the vagina. Its consistency varies from, thick and stringy to thin and watery. During the period around ovulation, cervical mucus is thin, watery and elastic in texture.

Checking your basal body temperature

Your basal temperature is your body temperature at rest. During the period after ovulation, the body’s basal temperature becomes slightly elevated and stays that way through the remainder of the menstrual cycle. Measuring your basal temperature can be a simple, inexpensive way of determining ovulation. But it’s important to note that your temperature will rise AFTER ovulation. You should, therefore, not wait until your temperature has risen to have intercourse, as you will have missed your most fertile time.

Basal Body Temperatures are taken each morning prior to getting out of bed to start the day. The temperatures are charted on a special graph to follow the rise in temperature. The rise is a small fraction of a degree, so it is helpful to purchase a special basal body thermometer, which has 1/10 of a degree ranges, plus charts to monitor your menstrual cycle. Basal body temperatures can rise for other reasons such as fever, stress, poor sleep, smoking and being overheated in your bed. Noting any physical changes on your basal body chart will help you evaluate your temperature pattern. This method works best after having several months of charts to compare the patterns in your basal body temperature. You should save all of your charts and so you can review them with your doctor. Three or four months of charting should be adequate to determine your pattern of ovulation.

Using ovulation predictor kits

These are kits available at drugstores that measure the amount of luteinizing hormone, which triggers ovulation, in urine. When the result is positive, ovulation will occur in the next 24 –36 hours. Ovulation kits have very specific instructions for use. Be sure to read the package insert fully before use. It is best to use an ovulation predictor kit after you have established your basal body temperature. Knowing your BBT pattern will give you a better idea of when to start using the ovulation predictor tests.

The Man

Healthy Sperm

While trying to determine your most fertile time of the month, it’s important to remember the man’s role in achieving pregnancy, too. Your partner is responsible for producing healthy sperm. In a healthy male with no history of infertility, over 50 million sperm are discharged during a single ejaculation. Many die off before they make it through the cervix. Others migrate to the woman’s non-ovulating side. A healthy sperm count helps assure that enough sperm get to the mature egg to attempt penetration and fertilization.

The following can effect the count or quality of sperm produced:

• smoking
• tight under garments
• elevated temperature
• regular use of hot tubs
• chronic alcohol use
• steroids
• opiates
• chemical or radiation exposures