Rhythm is great on the dance floor but it is a very difficult method for young women to use. It means abstaining from sex during the time of a women's cycle when she's likely to be fertile.

Advantages include:

• It's free.
• No complications of the method (except the possibility of unplanned pregnancy).

Disadvantages:

• It's only useful for women who have regular menstrual cycles.
• Careful planning is necessary.
• Serious discipline is required from both partners to make it work.

If a woman has regular menstrual cycles, she is most likely to become pregnant about two weeks after the first day of her period and for a couple of days before and after that time. Using the rhythm requires two (or three) cool heads particularly if the fertile time coincides with the prom. The discipline necessary is usually only found in the most mature couples. In my high school the question was "What do you call couples who use rhythm for birth control?" The answer: "Parents!"