Fertility Awareness And The Rhythm Method

Also known as natural family planning or periodic abstinence, fertility awareness entails not having sexual intercourse on the days of a woman's menstrual cycle when she is more likely to become pregnant, or using a barrier method of birth control on those days. Because a sperm may live in the female's reproductive tract for up to seven days and the egg may remain fertile for about 24 hours, a woman could get pregnant from intercourse that occurred from seven days before ovulation to 3 days after. Methods to approximate when a woman is fertile are usually based on the menstrual cycle, changes in cervical mucus, or changes in body temperature.   Natural family planning can work, but it takes an extremely motivated couple to use the method effectively.  In most cases the rhythm method is not effective or appropriate as a means of preventing unwanted pregnancy, but is a good method for spacing between children.

• Since it is difficult to know exactly when ovulation will occur, this method can be very unreliable and should be used only when no other, more reliable form of contraception is acceptable. Those who use this method most successfully are women whose cycles are predictable and regular, those who have had careful instruction and those whose partners are as committed to the method as they are.
  
  
• There are several ways to approach predicting fertile days, but a combination of these methods is more effective than any of the first three alone.
  
  
• Body temperature changes during the menstrual cycle, rising approximately 0.4 to 0.8° F on the day of ovulation. It remains at that level until the next period. Take your temperature every morning using a basal body temperature thermometer before getting out of bed and record it on a calendar. You are fertile for 3 days after ovulation.
• Cervical mucus - Following your period, observe the consistency of your vaginal discharge. Immediately following the period, it should be cloudy and a little sticky. It will change consistency a few days before ovulation, becoming clear. This is your most fertile phase.
• The calendar or rhythm method works by charting your menstrual cycle on a calendar. This works effectively only if your periods are the same from month to month.
• The symptothermal method mixes the body temperature, cervical mucus, and calendar methods together.
• The postovulation method requires you to abstain from intercourse or use a barrier contraceptive from the beginning of your period until the morning of the fourth day after your predicted ovulation.
  
  
• Many women who choose these methods are able-or think they are able-to tell when they are ovulating by a lower abdominal pain felt at mid-cycle called "mittleschmerz".  Other women use ovulation kits or a monitor called the Clear Plan Easy Fertility Monitor (which is approved to enhance fertility, not yet for contraceptive purposes) to assist with their fertility awareness means of preventing pregnancy.

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Created: 10/31/2001  -  Donnica Moore, M.D.