Fertility Awareness Based (FAB) Methods of NFP
All modern methods of NFP are based on Fertility Awareness, i.e. on a daily record of the changes in the fertility indicators, namely in ‘cervical mucus, basal body temperature and the cervix. They are therefore termed the Fertility Awareness Based (FAB) Methods of NFP. These methods of natural family planning are scientifically based on many years of research especially by the World Health Organization (WHO) among others. (see references 12-19 in Link The Development of NFP.
What are the FAB Methods of Natural Family Planning (NFP)?
There are two main FAB methods of Natural Family Planning:
- The symptothermal double-check method taught by our Association (NFPTAI).
- The Billings Method
How do these NFP Methods differ?
They differ in the number of fertility indicators used in each method.
(A) NFP methods that use more than one fertility indicator; the symptothermal double-check method uses the changes in two indicators ‘cervical mucus’ and the ‘calendar rule’ to define the beginning of the fertile phase, and the changes in two indicators ‘cervical mucus’ and ‘basal body temperature’ to define the end of the fertile phase .
(B) NFP methods that use just one fertility indicator; the Billings Ovulation Method uses the changes in one indicator ‘cervical mucus’ to define both the beginning and end of the fertile phase.
(A) NFP Methods using more than one fertility indicator:
The symptothermal methods of natural family planning use a combination of fertility indicators usually ‘cervical mucus’ and ‘basal body temperature (BBT)’ with or without other fertility indicators to define the beginning and end of the fertile phase. The ‘symptothermal double-check method’, (multiple index method), which is taught by the Natural Family Planning Teachers’ Association of Ireland (NFPTAI) uses two indicators of fertility, (‘cervical mucus’ and the ‘calendar rule’, whichever comes first), to identify the beginning of the fertile phase, and two indicators of fertility, (‘cervical mucus’ and ‘Basal Body Temperature’, whichever comes last), to mark the end of the fertile phase.
Initially the woman will be taught to observe all indicators (including palpation of the cervix), during the learning phase and from this initial combination, the woman can tailor the method to her particular circumstance by using the two indicators that are more convenient for her to mark the beginning and the end of the fertile phase. The following two fertility indicators ‘palpation of the cervix’ and the ‘calculation rule’ (‘calendar rule’) are never used alone, but only in combination with the ‘basal body temperature (BBT)’ and/or the ”cervical mucus’ indicators.
(B) Natural Family Planning Methods using just one fertility indicator:
There are three methods of natural family planning that use just a single fertility indicator:
- The ‘Billings Ovulation Method’
- The Creighton Model System
- The ‘Temperature Method’.
(i) Billings Ovulation Method: The ‘Ovulation Method’ also known as ‘Billings Method’ or the ‘Cervical Mucus Method’ uses cervical mucus observations at the vulva as a single fertility indicator to define the beginning and end of the fertile phase. The ‘Ovulation Method of NFP is used throughout the world.
(ii) The Creighton Model System is a single index method of Natural Family Planning using the observation of the mucus flow as the fertility indicator. Couples are taught specific instructions which they can use to either achieve or avoid a pregnancy, or to monitor Woman’s Health. See http://naprobaby.ie/ ; www.fccirl.ie (fertilityCare Centres of Ireland) & https://creightonmodel.com/
(ii) Temperature Method:
The Temperature Method is a single index method of Natural Family Planning using the basal body temperature as the fertility indicator. Couples wishing to avoid pregnancy are advised to restrict intercourse to the post-ovulatory phase, (i.e. the definitely infertile phase as defined by the RULES of the Temperature Method; the ‘definitely infertile phase’ is so called because the ovum is dead and no further ovulation will occur in that cycle).The Temperature Method is a highly efficient method of avoiding pregnancy but is used less often nowadays as it can only be applied to the post-ovulation phase, i.e. it can only detect the end of the fertile phase, and for this reason long periods of abstinence may be required.
Lactational Amenorrhea Method (LAM):
LAM is a Method of natural family planning which applies only to a particular situation, i.e. after childbirth, and it can only be applied for a limited period of time.1,2
References:
- Perez, A. Labbok, MH. Queenan JT. ‘Clinical study of the Lactational Amenorrhoea Method for family planning’; Lancet 1992; 339; 968-70
- Kennedy KI, Rivewra, R. McNeilly AS.; ‘Consensus Statement on the use of breastfeeding as a family planning method’; Contraception, 1989; 39 (5): 477-496
