Pregnancy - identifying fertile days

Information

When trying to make a baby, many couples plan intercourse around days 11 - 14 of the woman's 28-day cycle, when ovulation occurs. However, it is often difficult to know exactly when ovulation will happen. Doctors recommend that couples who are trying to have a baby have sex between days 7 and 20 of a woman's menstrual cycle. Studies have shown that having sex every other day or every third day works just as well as having sex every day in order to become pregnant.

Sperm can live inside a woman’s body for 3-5 days. However, a released egg only lives for 4 to 12 hours. The highest pregnancy rates have been reported when the egg and sperm join together within 4 to 6 hours of ovulation. So don't wait until you think ovulation has occurred to have sex.

Watch this video about:Ovulation

If you have an irregular menstrual cycle and are no sure when or if you are ovulating, ovulation predictor kit can help. These kits, which can be bought at most drug stores, check for LH (luteinizing hormone) in the urine.

There are other various other methods to help detect when you are most likely to be able to conceive a baby.

Note: Some lubricants can interfere with conception. If you are trying to get pregnant, you should avoid all douches and lubricants (including saliva), except those specifically designed to not interfere with fertility (such as Pre-seed). Lubricants should never be used as a method of birth control.

Evaluating Your Cervical Fluid

Cervical fluid protects the sperm and helps it move toward the uterus and fallopian tubes. Cervical fluid changes occur when the woman's body is getting ready to release an egg. There are clear differences in how it looks and feels during the woman's monthly menstrual cycle.

• During her period, no cervical fluid is present
• After the period, the vagina is dry and no cervical fluid is present
• It then turns to a sticky/rubbery fluid
• The fluid becomes very wet/creamy/white -- FERTILE
• The fluid becomes slippery, stretchy, and clear like an egg white  -- VERY FERTILE
• After ovulation, the vagina becomes dry again (no cervical fluid)

 You can use your fingers to see how your cervical fluid feels. Find the fluid inside the lower end of the vagina. Tap your thumb and first finger together -- if the fluid stretches while you spread your thumb and finger apart, this could mean ovulation is near.

Taking Your Basal Body Temperature

After you ovulate, your body temperature will rise and stay at a higher-than-normal level for the rest of your ovulation cycle. At the end of your cycle, it falls again.

You can use a special thermometer to take your temperature in the morning before you get out of bed. Use a glass basal thermometer or a digital thermometer so that you can get accuracy to the tenth of a degree. Keep the thermometer in your mouth for 5 minutes or until it signals you that it is done. Try not to move too much, as activity can raise your body temperature slightly.

If your temperature is between two marks, record the lower number. Try to take your temperature at the same time every day, if possible.

Create a chart and write down your temperature everyday. If you look at a complete cycle, you will probably notice a point at which the temperatures become higher than they were in the first part of your cycle. More specifically, the rise is when your temperature increases 0.2 degrees or more above the previous 6 days.

Temperature is a useful indicator of fertility. After monitoring several cycles, you may be able to see a predictable pattern and identify your most fertile days.

Alternative Names

Basal body temperature

References

Mishell DR. Family planning: contraception, sterilization, and pregnancy termination. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap 14.

Lobo RA. Infertility: etiology, diagnostic evaluation, management, prognosis. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap 41.

Update Date: 2/26/2012

Updated by: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.