Dr. MJ Bazos MD, Patient Handout
Natural Family Planning

What is natural family planning?

Natural family planning is a way to help a couple determine when sexual intercourse can and cannot result in pregnancy. During each menstrual cycle, one of a woman's ovaries releases an egg. This process is called ovulation. The egg moves toward the uterus through the fallopian tubes, where fertilization may take place. An unfertilized egg may live for 12 to 24 hours. The egg will be shed later during the menstrual period if it isn't fertilized. A woman is most likely to become pregnant if sexual intercourse takes place just before or just after ovulation.
During the menstrual cycle, a number of changes occur in a woman's body. By keeping track of these changes, couples can plan when to have intercourse and when to avoid intercourse, depending on whether they are trying to achieve or avoid pregnancy.

How does natural family planning work?

Two methods of natural family planning are currently taught. The first is the ovulation method. In this method, the days just before and just after ovulation are determined by checking the woman's cervical mucus. When a woman is most likely to become pregnant, the cervical mucus is stretchy, clear and slick. Some people say that the cervical mucus during this time looks and feels much like an uncooked egg white.
The second method is called the symptothermal method. With this method, the woman takes her temperature each day with a special thermometer and writes it down on a chart. At the time of ovulation, a woman's temperature will rise slightly. The woman also checks the consistency of her cervical mucus. She may also notice other changes, such as pain in the area of the ovaries, bloating, low backache and breast tenderness.
In both methods, couples use a special chart to keep track of the changes in the woman's body.

How effective are these methods in helping a couple avoid pregnancy?

These methods can help a couple avoid pregnancy if the couple receives training from a specialized instructor and if they carefully follow all of the instructions provided. (Ask your doctor how to find an instructor who is specially trained in teaching natural family planning.) Both methods can be 90% to 98% effective (2 to 10 pregnancies per 100 couples) when they are practiced correctly. However, if a couple doesn't follow the instructions completely, these methods will be much less effective. In practice, these methods may not be as reliable as other forms of birth control.

Can natural family planning help a couple achieve pregnancy?

Yes. As many as 2 out of 3 couples who don't have fertility problems become pregnant if they have sexual intercourse on the days that the cervical mucus is clearest and most stretchable.

What about the rhythm method?

The rhythm method is based on calendar calculations of previous menstrual cycles. This method doesn't allow for normal changes in the menstrual cycle, which are common. The rhythm method isn't as reliable as the ovulation method or the symptothermal method and is generally not recommended. Women who have no variation in the length of their menstrual cycles can use the rhythm method to know when they are ovulating (14 days before the start of their period).

What about women with irregular cycles or who are breast feeding?

It is common for a women to have menstrual cycles that are irregular (either longer or shorter than 28 days). A woman who has irregular menstrual cycles may still be able to tell when she is ovulating by watching for the changes in her body.
Special instructions have been developed for mothers who are breast feeding their babies. Ask your doctor for these instructions if you're breast feeding.

What are the advantages of natural family planning?

First, natural family planning does not involve the use of medicines, mechanical devices or chemicals. Side effects or risks that may occur with the use of such medicines or devices will not occur with natural family planning methods. Second, natural family planning methods are inexpensive. A fee is usually charged for instructional training and supplies, but there are no ongoing costs. Third, natural family planning methods require partners to share the responsibility for planning or avoiding pregnancy. Typically, couples who use these methods notice an increase in communication and in cooperation.