Natural family planning

Natural family planning is more than a method of birth control – it’s a way of life based on the biological fact that women are only able to conceive on certain days in the month. Its success depends on a couple avoiding sexual intercourse during the fertile days of the woman’s cycle. Its main drawback is that predicting the precise time of fertility is extremely difficult and involves some rather complicated calculations. Although there are today several more effective methods of contraception readily available, some people will still choose to use natural methods of family planning. They include those with religious objections, those who dislike interfering with their natural bodily functions (either with hormones or mechanical, aids) and are not too worried about becoming pregnant, and those who find that other methods produce unacceptable complications or side-effects.

One further feature of NFP is that both partners can share control over their fertility and the method is unique in that it can help couples wishing to conceive, by indicating the best times to have intercourse to achieve a pregnancy.

The traditional terms ‘rhythm method’ or ‘safe period’ used to describe types of birth control based on periodic sexual abstinence have been replaced in recent years by the term ‘natural family planning’. The overall aim of NFP is to teach couples to recognize the beginning and end of the woman’s fertile days so that they only have intercourse during the ‘safe’ times when pregnancy is unlikely to occur.

In a typical menstrual cycle (which varies between 20 to 36 days from woman to woman) the ovary releases one egg about 12 to 16 days before the next period is due. This is the fertile phase- called ovulation-when sexual intercourse is most likely to lead to pregnancy. The egg remains in the fallopian tube ready to be fertilized for about two days, and the man’s sperm can survive in the woman’s body for up to five days. It can be seen, then, that to avoid getting pregnant, you must not have sexual intercourse for several days before and after ovulation. However, the precise times will differ depending upon which of the four main NFP methods a couple chooses to use: the method, the method, the (or ovulation) method, or the method (combining different techniques).

While the various methods may sound fine in theory, actual clinical trials have shown that in practice, failure rates can be high indeed. As with any method of contraception, some failures must be expected, but with NFP methods, the rates are rather higher than with the chemical or mechanical methods, probably for two main reasons. First, there is still a great deal that is unknown about the precise workings of the reproductive system, and predicting the exact times of fertility is still not accurate. As you will notice, the ‘safe’ times in the month even differ slightly according to the method you are using-calendar, temperature or Billings. Secondly, both partners need to be highly motivated to avoid pregnancy as the various methods can be complicated to work out and, of course, mean that a thoroughly spontaneous sex-life is impossible.

Statistically, reported failure rates using the Billings method alone vary widely- from 15 to a staggering 39 per cent per year. This means that if you use this one method alone, you risk between 15 and 39 chances out of 100 of becoming pregnant in any one year. In contrast, clinical trials using the symptothermal method show a much-reduced failure rate- an average of 8 percent. There is no doubt, then, that combining methods will considerably improve protection against conception.


Defining the effects of natural family planning methods on a couple’s relationship is nearly as difficult as trying to generalize about how to practise the methods for large numbers of women- the individual holds the key to success.

As mentioned earlier, a spontaneous or casual sex life is simply not possible, as long periods of sexual abstinence are required to make the methods work. Although both partners take equal responsibility about when they need to abstain, inevitably there’ll be times when desire conflicts with this. The strains on both partners, if this occurs often, will soon be evident.

Some studies of female sexuality have suggested further, that women reach their peak of sexual desire around the time they ovulate. If this is so in your case, you may well find it is just too inhibiting to have to limit your sexual fulfilment to such an extent. Anxiety about becoming pregnant, even on ‘safe’ days, may also interfere with sexual fulfilment.

On the other hand, some people will find that by having to be closely in tune with one another physically, they may grow closer in other aspects of their relationship, and learn to express their love without full intercourse by exploring other ways of giving and receiving intimate sexual pleasure. Some advocates of NFP claim that periods of abstinence can lead to a greater appreciation of the quality of sexual intercourse that they do enjoy. And, of course, since you do not have to use any form of mechanical device during actual love-making, you may feel a greater sense of sexual freedom.

Are there any dangers or side-effects as with some other contraceptive measures? One big advantage of NFP methods over other chemical, hormonal or mechanical means of contraception is the absence of physical side-effects. However, it must be noted that recendy scientists have been conducting more detailed studies of NFP methods in a search to perfect them and to determine more specifically if there are any possible long-term side-effects.

One factor which has come to light concerns the occurrence of an unplanned pregnancy. It appears from studies of animals, and from birth statistics in largely Catholic countries where NFP is widely practised, that the birth of a congenitally abnormal child might be more apt to occur if conception happens between an ageing ovum or a deteriorating sperm. However, many doctors disagree with this theory. Certainly, at this stage it is merely an interesting speculation with no conclusive evidence yet found to back it up. Research into NFP methods continues all the time.

How can you decide whether NFP is suitable for you? How can you learn to use it? If you are trying to find a suitable method of contraception and are in general good health, most experts would not recommend NFP methods to you as a first choice- the scope for error with them is still fairly great. However, if you have found that other methods really do not suit you and if you can realistically accept the higher risks of pregnancy involved, then these methods may be just right for you.

An older woman with perhaps one or two children already who feels she wants to stop taking the Pill as the risks to her health increase, may find that she and her husband can use NFP without much difficulty- especially if a further pregnancy would not be a disaster for them.

However, a young, single woman could find them practically impossible to implement, and an older woman beginning to go through the menopausal changes would most likely find it difficult to use the normal indicators – I.e. temperature shift or mucus change – with any certainty. Women who have recently given birth will find difficulties for similar reasons – their bodily functions are likely to be very changeable. If you have very irregular periods or unusual difficulties with menstruation, you would be better advised to try another method of contraception if possible.

For those who do choose N FP, learning how to practise the methods requires individual tuition and cannot be done solely by following instructions in a book. Most local family planning clinics now can provide some of the necessary advice and information, but are likely to refer you to special tutors.

These tutors, who are available in many areas, can give each couple specific training- especially in interpreting mucus changes and temperature charts. They are helpful in providing moral support for both partners, and are essential for those women who must use NFP, perhaps for religious reasons, and who have various irregularities in their reproductive functions – after childbirth, menopause, etc.

With the growing awareness of the possible long-term effects in other, birth control methods -namely the Pill and IUD – scientists have been working much more on trying to find an aid that will accurately predict when a woman ovulates and becomes fertile. Many developments have come about as a result of studies done to help infertile couples. By and large they are still confined to the laboratory.

One such aid is known as a urine ‘dip-stick’. This test involves dipping special paper into your urine daily. The colour of this paper will change as the amount of in the urine increases. This hormone is one of several which are essential in the female reproductive cycle, and it is known that its level of production rises sharply just before ovulation. To date the test only detects when you have ovulated; it has not been proved accurate in predicting it. Home- kits based on this finding are being investigated.

Another aid which has been developed, is known as an ‘intelligent’ thermometer. Basically it incorporates a computer memory bank so that a woman using the basal body temperature method need not rely on charts. She merely takes her temperature in the usual way and the machine will store the information and give her a green light go-ahead when three successive days of a temperature rise are noted and she is safely past her fertile phase. It includes a fail-safe mechanism for bouts of illness.

While in the future these devices may un-doubtedly help users to practise NFP more effectively and scientifically, critics would question just how ‘natural’ it is to use a method that relies on abstinence for about half of each menstrual cycle, and requires daily observation and recording using calendars, charts, thermometers, graphs or other implements. But that aspect must be for couples to decide themselves, weighing the benefits against the disadvantages.