Recent Articles on NFP

The teacher training course is now underway! Best wishes to all the students.

Course Director Deirdre Gleeson has recently published a number of articles on NFP.  The first, posted below, is from the Irish Medical Times.

Fertility Awareness Based Methods (FABM) of Family Planning

The world health organisation defines fertility awareness-based methods (FABM) of family planning as “methods that involve identification of the fertile days of the menstrual cycle, whether by observing fertility signs such as cervical secretions and basal body temperature, or by monitoring cycle days. FABM can be used in combination with abstinence or barrier methods during the fertile time.” (1)  Natural family planning is a particular FABM that promotes abstinence during the fertile days and is acceptable to people of all faiths and cultures. (2)

Examples of FABM include the Justisse method, which relies on body literacy for natural birth control (3), the standard days method, the two-day method (4,5), the Creighton method (6) and of course nowadays couples can use technology to assist their fertility awareness with ovulation predictor kits such as Persona and iPhone apps such as iCycle and Kindara. The out dated rhythm method used calendar data only and was unreliable and has not been recommended by family planning groups for many years.  

Modern FABM are a reliable alternative to artificial family planning. Many women are concerned about the potential risks to their health and the environmental impact from hormonal and other artificial contraceptive methods. FABM offers couples a method to plan or avoid a pregnancy that is safe, effective and free from side effects.

The aim of FABM is to enable the couple identify the days during the woman’s menstrual cycle when she is fertile and adjust their sexual behaviour during this time according to their family planning intention. The fertile phase lasts for only six days every cycle, this accounts for 5 days of sperm survival in the female genital tract and 24-hour survival of the ovum after ovulation. As our understanding and knowledge of the science of the fertility cycle improves it is possible to more and more accurately identify these 6 days and thus the beginning and end of the fertile phase.  

The simplest method of identifying the fertile phase uses the cervical mucus sign and this forms the basis of the popular Billings method (7,8). Studies on the efficacy of Billings give a reliability of 97.1%. The sympto-thermal double check STDC method uses multiple fertility indicators: basal body temperature, mucus, cervix position and other minor signs to give a Pearl Index for Actual Use of 98.2% (9) which compares well with artificial contraceptive methods.  

Couple motivation and proper instruction by a qualified teacher are key to successful FABM. Most couples require 3 months of instruction to become autonomous in confidently identifying the fertile and infertile phase of the cycle. The NFPTAI (Natural Family Planning Teachers Association of Ireland) trains and supports teachers in the evidence-based symptom-thermal double check method of natural family planning (NFP) since 1988. The next teacher training course starts in September 2016 in Swords, Co. Dublin with 6 weekends of lectures over 6 months followed by 3 months of supervised practical training in instructing couples on the art of NFP.

Dr Deirdre Gleeson Course Director NFPTAI


  1. World Health Organization: Fertility Awareness Methods–Health for all 2000. Report on a WHO Workshop. Poland, WHO 1986
  2. 2. Pyper CMM: Fertility Awareness & Natural Family Planning. Eur J Contracept Reprod Health Care 2:131-146, 1997
  3. 3. Justisse Healthworks for Women, Fertility Awareness Education, Natural Birth Control & Holistic Reproductive Health
  4. 4. Arévalo, M., Jennings V., Nikula M., and Sinai I. (2004). “Efficacy of the new TwoDay Method of family planning”. Fertility and Sterility 82(4):885-892
  5. The FAM project (two day method, standard days method, lactational amenorrhoea method) Institute of Reproductive health Georgetown University

6 Hilgers T, Stanford J. Creighton Model NaProEducation Technology for avoiding Pregnancy: Use Effectiveness. J Reprod Med. 1998 Jun;43(6):495-502.

  1. Trials of the Billings Ovulation MethodThe Billings Method, Dr. Evelyn Billings & Ann Westmore. First Ed: 1980, Newest Ed 2011
  2. The Billings Method: World Organisation of Ovulation Method Billings. National Association of Ovulation Method in Ireland.
  3. Frank-Herrmann et al; ‘Human Reproduction 2007 May;22(5):1310-9. The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple’s sexual behaviour during the fertile time: a prospective longitudinal study.
  4. NFPTAI. Course in fertility awareness.


The following articles are from The Open Door newspaper.

Natural Family Planning:

The Cervical Mucus Sign

The presence of fertile cervical mucus is the most important sign of fertility. Without cervical mucus there is no chance of pregnancy and even a tiny drop of mucus at the vulva is enough to attract and transport sperm through the female genital tract. This is why there are many examples of pregnancy occurring without penetration.

The cervix is a complex organ that responds to hormones produced by the ovary during the fertility cycle. Oestrogen produced by the developing follicle in the first half of the cycle stimulates glands in the cervix to produce fertile mucus. This is recognised by the woman as cloudy or clear, wet and flowing in increasing abundance as oestrogen levels soar in the week prior to ovulation. She records the sensation, appearance and quantity of mucus observed at the vulva in her fertility chart and she knows that the presence of fertile mucus indicates the pre-ovulatory fertile phase of her cycle when pregnancy is possible.  

Up to five hundred million sperm are deposited at intercourse and they depend on cervical mucus for their survival in the female genital tract. In the absence of fertile mucus sperm will die in a matter of hours, but in the presence of fertile mucus sperm can live for up to 5 days.

Cervical mucus transports, nourishes, filters and attracts male sperm. The mucus filters out defective sperm while allowing healthy sperm to swim upwards through specially designed mucus-channels to the uterus and the fallopian tube to await the arrival of the egg at ovulation. Some sperm are diverted by the mucus to special crypts in the cervix where they are nourished to be released later as ovulation draws near. If there is no sperm and fertilization does not occur the egg dies within 24 hours of ovulation.

After ovulation, the corpus luteum releases progesterone which causes the cervical glands to cease producing fertile mucus and switch to producing infertile mucus. This is recognised by the woman as thick, sticky, opaque and scant in quantity. The cervix becomes plugged with this infertile mucus preventing any more sperm gaining entry and also protecting any future pregnancy against infection. The woman notices an abrupt change from fertile to infertile mucus and this enables her to retrospectively identify the last day of fertile mucus; the Peak day. Studies show that ovulation usually occurs within a day of the Peak.   

The woman and her partner must wait for 4 days (Billings rules) or 3 days with a temperature rise (Symptothermal rules) following peak day before being certain that they are in the post-ovulatory infertile phase of the cycle with no chance of pregnancy.   

Cervical mucus is designed to optimise the chances of pregnancy. Natural family planning embraces this amazing fact and works with nature rather than artificially inhibiting the normal, healthy, mid-cycle mucus flow.

The fertility cycle and the dance of hormones

Fertility awareness methods of family planning rely on the interpretation of the signs of fertility to accurately identify the fertile and infertile phases of the woman’s menstrual cycle. Every month a wonderful dance of hormones takes place in a woman’s body to maximise the chances of a successful pregnancy. This ebb and flow of hormones is called the fertility cycle. Women are designed for fertility and natural family planning NFP endeavours to work with a woman’s fertility rather than interfering with this natural process by artificial means.

The menstrual flow signals the end of one cycle and the beginning of the next and is precipitated by the fall in Oestrogen and Progesterone levels that occur at the end of a cycle. Oestrogen and Progesterone have a negative feedback effect on the hypothalamus in the brain and when this negative switch is removed the hypothalamus wakes up and releases Follicle Stimulating Hormone FSH. In the first half of the fertility cycle FSH stimulates the development of several follicles in the ovary, one of which will eventually dominate to produce the ovum or female egg. The ovarian follicles produce Oestrogen which in turn stimulates the lining of the uterus (the endometrium) to proliferate and prepare a bed in anticipation of embryo implantation in the second half of the cycle. Oestrogen acts on the cervix to stimulate production of mucus and also causes the cervix to soften and open to facilitate the passage of sperm.

As our scientific knowledge of the cervix increases we are beginning to understand how this incredibly complex organ functions to promote fertility. Towards mid cycle the structure and amount of mucus produced by the cervix changes to maximise transport of male sperm through the female genital tract. When the woman notices the mucus flowing at mid cycle, she knows that an egg is ripening in her ovary and that ovulation is pending and that she is now in the fertile phase of her cycle.

Up to 500 million sperm are deposited in the vagina during the act of intercourse. Cervical mucus attracts, transports and nourishes this sperm and also filters out defective from healthy sperm. Male sperm can survive for 5 days in the female genital tract hidden away in specially designed crypts in the cervix. The sperm are released from these cervical crypts in coordinated waves and swim upwards through the uterine cavity and fallopian tube to await the arrival of the female egg at ovulation.

**At ovulation, the delicate fimbriae (hair like) projections of the fallopian tube sweep harmoniously over the surface of the ovary to capture the egg and bring it towards the awaiting sperm. Fertilization takes place at the end of the fallopian tube as one of the awaiting sperm fuses with the egg to form a unique human being, with his or her own genetic makeup. The fertilized egg is now called the embryo and this tiny human which is perfect for its stage of development begins to grow rapidly as it’s cells divide and organise to form a tiny human body, a placenta and membranes. The embryo moves slowly down the fallopian tube over the next week to its destination and home for the next 9 months in the uterine cavity.  

Oestrogen in the first half of the woman’s cycle stimulates the brain’s hypothalamus to produce Luteunizing Hormone (LH), which is the trigger for ovulation. After ovulation, the ruptured follicle in the ovary becomes the corpus luteum (yellow body) which produces the hormone Progesterone. Progesterone stimulates the secretion of glycogen in the lining of the uterine cavity to form a soft nutritious nest to receive the embryonic sac at implantation. The newly formed embryo produces the hormone Human Chorionic Gonadotrophin (HCG), which keeps the corpus luteum in the ovary alive and active until the placenta is developed enough to take over the production of Progesterone and other hormones necessary for the progression of a healthy pregnancy. Progesterone from the ovary after ovulation causes the woman’s basal body temperature to rise and enables her to identify the infertile phase in the second half of her cycle.

Progesterone also acts on the cervix to cause mucus production to cease abruptly and to close the opening of the cervix tightly so that no more sperm can gain entry. The woman can learn to monitor the changes in position, opening and firmness of her cervix to help identify the fertile and infertile phases of her cycle.

If no ovulation occurs, the egg dies within 24 hours and there is no embryo to produce HCG, so the corpus luteum dies and the production of Oestrogen and Progesterone from the ovary ceases. Without the support of these hormones the lining of the uterus breaks down exposing the basal arteries and causing the flow of blood that heralds the beginning of another cycle.  

Fertility awareness empowers a woman to read the changing signs of fertility throughout her fertility cycle to identify the fertile phase when pregnancy is likely and the infertile phase when pregnancy cannot occur. The couple then adjust their sexual behaviour to either plan or avoid a pregnancy according to their family planning intention.

Basal body temperature and ovulation

Basal body temperature (BBT) is the temperature of the body at rest, that is on wakening after at least 3 hours uninterrupted sleep. The small rise in BBT that occurs in the second half of the cycle was first recognised in the 19th century and later understood to be related to the thermogenic effect of the hormone progesterone released from the corpus luteum after ovulation. This rise in temperature indicates that the egg has left the follicle (ovulation) and the follicle has become the corpus luteum and is now producing progesterone to prepare the lining of the uterus in anticipation of conception and implantation. This rise in BBT allows the woman to retrospectively identify the end of the fertile phase (pre ovulatory) and the beginning of the infertile (post ovulatory) phase of her menstrual cycle.

The rise in BBT is a very reliable fertility indicator and can be used on its own as a single index method of natural family planning (NFP) or in combination with the mucus sign and other signs in multi-index methods of NFP such as the symptom-thermal double check method.

The woman remembers to take her temperature using a special fertility thermometer every morning on wakening, before getting out of bed, before eating or drinking, at the same time and using the same thermometer. She records the reading in her fertility chart or on her fertility app.

In a normal cycle the temperature chart is biphasic, with lower readings in the first half of the cycle and higher readings in the second half of the cycle. A monophasic chart occurs when there is no ovulation and no temperature rise and this is useful when investigating the causes of infertility. After conception and implantation, the woman’s progesterone level soar and her BBT rises even further and this can be used to confirm pregnancy.

The post ovulatory rise in temperature is called the thermal shift and this means there has been a sustained rise in temperature for 3 days of a minimum of 0.20C or 0.40F above a line covering the previous 6 readings (“the three over six rule” and “the cover line”). In the temperature only method of NFP the couple must wait until the 4th day of higher temperature readings before being certain that they are in the post ovulatory infertile phase of the cycle when intercourse can take place without any chance of pregnancy.  The temperature rules are the easiest NFP rules to learn and most couples can confidently recognise the thermal shift after only two or three cycles.

A woman’s BBT may be sensitive to disturbances such as illness, excess alcohol and even stress, therefore the couple require proper training and instruction to measure the BBT accurately and how to manage temperature disturbances.

Since the rise in temperature is relatively small a highly accurate fertility thermometer is required. Digital fertility thermometers are the easiest to use and are available on-line. For further information on the temperature sign, recommended thermometers and the upcoming course in fertility awareness see the Natural Family Planning Teacher Association of Ireland website.

Breast feeding and natural family planning

Breast milk perfectly meets the nutritional needs of the growing baby. The World Health Organisation recommends that where possible a baby be exclusively breastfed for 6 months without any supplemental bottle feeds. Breast feeding can continue following the introduction of solids at 6 months for up to 2 years and beyond for as long as mother and baby are happy. Breast is best for baby and is also nature’s way of spacing births.

During pregnancy the high levels of oestrogen and progesterone inhibit ovulation and when these hormones fall rapidly following birth ovulation can occur as early as 27 days. A Mother who bottle feeds and wishes to use natural family planning (NFP) must begin charting her fertility indicators when her baby is 21 days old.

During breast feeding (lactation) the hormone prolactin which is responsible for milk production inhibits ovulation and therefore prevents pregnancy. Each breast feed stimulates further production of prolactin and ongoing suppression of ovulation and amenorrhoea (no periods). A woman who exclusively breast feeds can rely on the lactational amenorrhoea method (LAM) of natural family planning and consider herself infertile until 6 months postpartum providing she meets all of the following LAM criteria:

  1. The baby is less than 6 months old.
  2. The baby is exclusively breastfed & feeds at least every 4 hours by day & every 6 hours by night.
  3. The mother has not experienced any vaginal bleeding after 56 days postpartum.

As soon as the mother does not meet the LAM criteria she must begin charting and following the NFP rules. A mother who continues to meet the LAM criteria must begin charting at 5 months in preparation for the 6-month deadline. However, there is often no signs of fertility for some more months.

A partial breast feeder is a mother who also uses supplementary bottle feeds and therefore she falls outside the LAM criteria and must start charting from Day 21.

Natural family planning following childbirth is one of those special circumstances when special rules apply and the couple must be instructed and supported by a qualified NFP teacher. If you would like to become an NFP teacher, please see the NFPTAI website for details of the course in fertility awareness beginning in September 2016 in Swords.


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