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Natural Family Planning

Natural Family Planning (NFP) refers to a variety of methods used to plan or prevent pregnancy, based on identifying the woman's fertile days. For all natural methods, avoiding unprotected intercourse during the fertile days is what prevents pregnancy. Natural methods are also known as fertility awareness-based methods.

The effectiveness and significant advantages of NFP address the needs of diverse populations with varied religious and ethical beliefs. They also provide an alternative for women who want to use natural methods for medical or personal reasons.

Of married women worldwide using some form of family planning, approximately 8% claim to use a form of periodic abstinence. Yet a very small percentage of these couples actually are using a natural method correctly.
~Levels and Trends of Contraceptive Use, United Nations, 1999

New Simple Methods of Natural Family Planning

The Standard Days Method®

The Standard Days Method (SDM) is a new simple fertility awareness-based method. It relies on a "standard rule" or a fixed "window" of fertility that makes it easy for women to know when they are likely to become pregnant.

The fact that it involves no calculation or observation makes the SDM easy for service providers to teach and for women to learn and use. To avoid pregnancy, a woman with cycles between 26 and 32 days long should not have unprotected intercourse on cycle days 8 through 19.

A color-coded string of beads, called Cycle Beads™, are used to help women keep track of the days of their menstrual cycle and see which days they are likely to get pregnant. More on the SDM...

Clinical trials conducted in Bolivia, Peru, and the Philippines determined the effectiveness of the Standard Days Method. It is more than 95% effective when used correctly.
~Contraception, 2002

The TwoDay Method®

The TwoDay Method is a new simple approach to NFP. It relies on a simple algorithm to help women identify when they are fertile, based upon the presence or absence of cervical secretions.

If the woman notices any secretions on the current or previous day, then she is probably fertile today and should not have unprotected intercourse if she wants to avoid pregnancy.
If she notices no secretions today and yesterday (two days in a row without secretions), then she is not fertile today. More on the TDM...

Results of TwoDay Method clinical trial conducted in Guatemala, Peru and the Philippines showed that the method is more than 96% effective in preventing pregnancy when used correctly.

~Fertility and Sterility, 2004

Other Natural Family Planning Methods

The Ovulation Method

The Ovulation Method, also call the Cervical Mucus Method, is based on understanding and interpreting changing cervical secretions that are produced at the neck of the uterus (cervix). At the time of greatest fertility, these secretions become clear, stretchy, slippery and wet.

Couples who wish to avoid pregnancy abstain from intercourse from the onset of cervical mucus symptom until three days after the last day of fertile-type secretions.

Basal Body Temperature (BBT)

Women using the Basal Body Temperature (BBT) Method identify their fertility by observing their body temperature each morning before beginning any activity.
The body temperature is lower before ovulation and rises slightly to about .2 degrees Celsius or .4 degrees Fahrenheit after ovulation.

Couples who wish to avoid a pregnancy abstain from intercourse from the onset of menses until three days after the woman's basal body temperature has risen, to about .2 degrees Celsius or .4 degrees Fahrenheit, signifying the end of the fertile phase.

Symptothermal Method

The Symptothermal Method involves observing changes in the cervical secretions, along with changes in the basal body temperature, and the position and feel of the opening of the cervix. Other fertility signs such as mid-cycle pain or bleeding may accompany ovulation.

Couples who wish to avoid pregnancy abstain from intercourse during the fertile period identified by all of the fertility indicators.

Lactational Amenorrhea Method

The Lactational Amenorrhea Method (LAM) is based on scientific evidence that a woman is not fertile and unlikely to become pregnant during full lactation or exclusive breastfeeding. Full lactation describes breastfeeding when no regular supplemental feeding of any type is given (not even water) and the infant is feeding both day and night with little separation from the mother.

LAM provides maximum protection as long as:

  • Menstruation has not resumed and
  • Bottle feeds or regular food supplements are not introduced and
  • Baby is less than 6 months of age.

Effectiveness of Natural Family Planning Methods

Successful use of natural methods to prevent pregnancy depends upon:

  • The accuracy of the method in identifying the woman's actual fertile days
  • A couple's ability to correctly identify the fertile time
  • The couple's ability to follow the rules of the method they are using

Unintended pregnancies among women practicing natural methods are primarily related to user error. A sizable but unknown portion of the unintended pregnancies is attributable to improper teaching and poor use of the methods. Experts at the World Health Organization (WHO) suspect that among users of NFP, sexual-risk taking during fertile days--that is, having intercourse even when they know the woman is fertile--accounts for more unintended pregnancy than does inability to accurately identify the fertile time.

Couples who use natural methods correctly to prevent pregnancy have only a 1% to 9% chance of becoming pregnant during one year of use, depending on which method they use.
Couples who do not use their method correctly—that is, they have intercourse on days when the method's guidelines tell them that the woman is fertile—-have a much greater chance of unintended pregnancy.

The following is the probability of pregnancy for women using natural methods:

Advantages and Disadvantages of Natural Family Planning Method


  • Increased self-awareness and knowledge of their fertility
  • Increased reliance on their own resources rather than a family planning program or other sources of contraception
  • Increased independence from costly or distant medical services
  • Freedom from artificial substances and the side effects or potential medical risks of other methods
  • Reduced re-supply costs associated with commodity-based methods
  • Enhanced communication and intimacy with partner
  • Encourages male involvement in family planning
  • For some, the ability to adhere to religious and cultural norms


  • The commitment, motivation and cooperation of both partners is necessary
  • For women using symptom-based methods, keeping daily records of fertility signs and symptoms
  • When used for pregnancy prevention, a couple may experience stress as a result of not being able to have unprotected intercourse for several days in a row during the fertile days