Natural Family Planning

What is natural family planning?

Natural family planning is a term used for methods of birth control that do not involve the use of any drugs or devices. It is also called the rhythm method, fertility awareness, or periodic abstinence. If you do not want to get pregnant, you should not have sex during the days in your menstrual cycle when you are more likely to get pregnant (your fertile days). Using natural family planning for birth control requires a strong commitment from both partners.

Normally during each menstrual cycle one of your ovaries releases an egg. This is called ovulation. The egg travels through the fallopian tube to the uterus. Pregnancy happens if the egg is fertilized by sperm as it travels to the uterus. If the egg is not fertilized, your body absorbs it or gets rid of it when you have your period.

Sperm can live inside your body for 3 days after you have sex. This means that you can get pregnant up to 3 days after you have sex if you ovulate during that time.

How can I know when I’m fertile?

Natural family planning methods are based on calculating which days of your menstrual cycle are your fertile days. The length of the menstrual cycle varies from woman to woman. It can also vary month to month. An average menstrual cycle lasts 26 to 32 days. However, some women normally have regular cycles as short as 21 days or long as 35 days. Natural family planning methods depend on accurately recording information about your menstrual cycle and calculating safe days for sex. There are several ways to do this:

• basal body temperature
• cervical mucus or ovulation
• symptothermal method
• calendar method
• standard days method

Symptoms like pain in the area of the ovaries, low backache, breast tenderness, and bloating can help you know which days you are fertile. You may also buy ovulation kits in a pharmacy without a prescription. The kits can tell you exactly when you ovulate. They are simple to use. You put a sample of your urine on the test strip. The test strip is sensitive to changes in hormones and will change color if you are ovulating.

Usually your menstrual periods are more regular when you are 20 to 40 years old. For this reason, natural family planning is more effective if you are in this age group.

If you choose to use natural family planning birth control, you should avoid having sex, or you should use another, nonhormonal method of birth control, until you have figured out when your fertile days are most likely to happen. Taking hormones, such as birth control pills, will interfere with your normal hormonal cycles and keep you from knowing what your normal cycle is. However, barrier methods, such as diaphragms, condoms, and spermicides will not affect your natural family planning measurements.

You and your partner should be comfortable with your choice of a natural family planning method before you use it as your only method of birth control.

How do I use the basal body temperature method?

Basal body temperature (BBT) is your temperature when you wake up from sleep in the morning. Your BBT is a little higher when you ovulate. If you record your BBT every day for several months, you'll learn which days are your fertile days. You will need to measure your temperature with a special, basal body thermometer, which you can buy at the drugstore. It lets you measure very small changes in temperature. Take your temperature right after you wake up. Do it before you get out of bed, eat, drink, smoke, or have sex. Just after you ovulate your temperature will be about 0.5 to 1°F (0.5°C) higher. It will stay higher until your next period starts. If you do not want to get pregnant, you should not have sex from the time your period ends until 3 days after your temperature rises. For most women, this time to avoid sex will last for about 2 weeks. Write down your BBT every day on a calendar.

When you use this method of birth control it is important to remember that illness and any drugs, including alcohol, can raise your body temperature.

How do I use the cervical mucus or ovulation method?

Cervical mucus is a jellylike vaginal discharge that comes from the cervix. The cervix is the opening of the uterus into the vagina. The mucus is thick and sticky during most days of the menstrual cycle. It usually gets clear, thin, and watery (like uncooked egg white) about 4 days before ovulation.

You can check the cervical mucus with your finger or a piece of toilet paper. Days when the mucus is clear, thin, and watery are called wet days. If you do not want to get pregnant, you should not have sex from the time the watery mucus appears until 4 days after the mucus gets thick, sticky, and smaller in amount. Be careful that you don't confuse wet-day mucus with semen that leaves your vagina after sex.

How do I use the symptothermal method?

The symptothermal method uses a combination of the basal body temperature and cervical mucus methods to know when you could get pregnant. You will need to check your temperature and cervical mucus every morning. Combining the 2 methods may slightly improve your ability to predict ovulation, but it is more time consuming.

How do I use the calendar method?

The calendar method is also called menstrual charting. You must keep track of how long each menstrual cycle is. Do this for 8 cycles. Then you can calculate the days that you are most likely to get pregnant: Subtract 18 days from the number of days of your shortest cycle, and subtract 11 days from the number of days of your longest cycle. Use this range of days to know when your fertile days are most likely to happen. For example, if the shortest number of days in your menstrual cycle is 28 days, 28 - 18 = 10. If the longest number of days in your menstrual cycle is 32 days, 32 - 11 = 21. This would mean that you are most likely time to get pregnant between 10 and 21 days after you start having your period each month. If you do not want to get pregnant, you should not have sex during this time.

How do I use the standard days method?

On a calendar, mark and circle the day when your period first begins as Day 1. Then mark and circle the same day of the week, 1 week later, as Day 8. Count forward to Day 19 and circle it. Draw a solid line through days 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19. Days 8 through day 19 are days when you are more likely to get pregnant. For these 12 days (days 8 through 19), do not have sex if you want to avoid getting pregnant.

All other days in each cycle have a low risk of pregnancy. You can have sex on days 1 through 7 and on day 20 and the days after that until your next period starts. Mark the day your next period starts as Day 1 of the next cycle. Then go back to the previous cycle on the calendar and count the total number of days in the previous cycle. Put a square around the total number of days for that cycle and do the same thing for each following cycle. If a cycle was 30 days long, the last day will be marked 30. Keep these calendar pages, so that you have a record of how long each cycle was.

This method works if no more than 1 cycle per year is less than 26 days long or more than 32 days long. If more than 1 cycle per year was shorter than 26 days or longer than 32 days, use a different method of natural family planning.

Can I get pregnant when I’m breast-feeding?

Frequent breast-feeding can prevent ovulation and keep you from having menstrual periods. You may use this as a method of birth control if your baby is not taking any other foods or formula. You must breast-feed at least 8 to 10 times per day, with no more than 6 hours between feedings, if you do not want to get pregnant. You should not use this as a method of birth control if you are not breastfeeding this often. You should also not use it if you are feeding your baby other foods or formula or if you start having menstrual periods again.

How effective is natural family planning?

Natural family planning can be 91 to 98% effective when one of these methods is used correctly all of the time. However, this is hard for most couples to do. If you do not follow the instructions completely, or if you have irregular menstrual periods, these methods are much less effective. They are less reliable than some of the other forms of birth control. Women who should not get pregnant for health reasons should not use natural family planning as a method of birth control.

What are the benefits?

The advantages of natural family planning are:

• You can have some control over when you have children without using drugs or devices.
• You can enjoy sex without the interruption or discomfort of barrier methods of birth control, such as condoms or diaphragms.
• You can avoid the health risks of some methods such as birth control pills and the IUD.
• It costs very little.

What are the disadvantages?

Natural family planning has several disadvantages, which include:

• If it is not practiced carefully, the failure rate can be as high as 25%. This means 2 to 3 of every 10 women get pregnant during 1 year of use.
• There are days every month when you should not have sex.
• It requires time, energy, commitment, and careful record-keeping.
• It does not protect against sexually transmitted diseases, including HIV/AIDS.

How can I learn more about natural family planning?

You can go to a class to learn more about natural family planning. Don’t try this form of birth control until you and your partner have had the class and are comfortable with it.

For more information on family planning, contact your healthcare provider or the following organizations:

• Office on Women's Health
  Phone: 800-994-9662
  Web site: http://womenshealth.gov/
• Institute for Reproductive Health
  Phone: 202 687-1392
  Web site: http://irh.org.