Rhythm Methods Of Contraception

Rhythm methods are all based on the concept of avoiding sex during the most fertile part of a woman’s monthly cycle. The original (calendar) method of birth control has been around for many years, and was pioneered to a large extent by the famous Marie Stopes. Unfortunately the contemporary understanding of the timing of the ovulatory cycle was very limited and often faulty, which presumably led to quite a few unwanted pregnancies!

However, it began the detailed investigations into the ovulatory cycle and ways of using this understanding as an aid to contraception. In the intervening years much progress has been made in ways of pinpointing the woman’s most fertile time, including analysis of her temperature, blood hormone levels and cervical mucus, and also by recognizing other factors such as mid-pain, bleeding patterns, breast discomfort etc.

Meanwhile, first the mechanical and then the hormonal methods of birth control were receiving increased publicity, plausibility and use. Women began to feel that they at last had safe, reliable, trouble-free methods of contraception, which tended to make them turn away from the more complicated rhythm methods. This did not apply so much to Roman Catholics, as rhythm methods are still the only birth control methods sanctioned by the Catholic church. However, the last few years have seen many women turning back to rhythm methods, for several reasons.

First of all, many of the ‘safer’ methods have been in part discredited. IuDs are linked with increased incidence of pelvic inflammatory disease, ectopic pregnancies and perforation of the uterus, as well as being proved in some cases to prevent implantation of the fertilized egg rather than prevent fertilization. The pill has been linked with various minor and more serious side-effects, even death, in some users, and some women are now not recommended to take the pill because of certain pre-existing medical conditions.

Secondly, advances in some of the rhythm methods have made them, theoretically at least, more reliable. Thirdly, many women have reacted against using chemical, mechanical or hormonal methods of birth control, and are preferring to use a method which makes use of a woman’s natural fertility cycle — hence the common name of ‘natural family planning’. Fourthly, stress has rightly been laid recently on the importance of couples taking joint responsibility over such important decisions as family planning; rhythm methods require the full co-operation of both the man and the woman to be successful.

On the surface, today’s rhythm methods can look like an ideal choice for the Christian couple. However, as with every other method of birth control, there are important ethical considerations to be taken into account. I feel that there are two serious ethical objections to the rhythm method, and several more minor considerations to be taken into account.

The first serious objection is that regular abstention from sex for contraceptive purposes militates against the biblical concept of sex within marriage. The biblical idea of sex within marriage is that it is a beautiful gift to be enjoyed freely within marriage as a special expression of love, not just to create children. The New Testament details guidelines for giving oneself joyfully and unstintingly to one’s partner, and mentions specifically that there is only one reason for sexual abstinence within marriage:

The husband should fulfil his marital duty to his wife, and likewise the wife to her husband. The wife’s body does not belong to her alone but also to her husband. In the same way, the husband’s body does not belong to him alone but also to his wife. Do not deprive each other except by mutual consent and for a time, so that you may devote yourselves to prayer. Then come together again so that Satan will not tempt you because of your lack of self-control (1 Cor. 7.3-5).

As Tim and Beverly La Haye say in The Act of Marriage: ‘In this passage of Scripture, every husband and wife are absolutely commanded to do that which satisfies their marriage partner.’ The Bible spells out that husbands and wives are not to abstain from sex except for a certain length of time for prayer; even then Paul makes sure that he enjoins them to ‘come together again’. This injunction from the word of God makes it very hard to credit Ingrid Trobisch’s remark in The Joy of Being a Woman that ‘natural family planning corresponds to the Biblical image of man’.

The rhythm methods of birth control are often described as carrying no risk to woman or baby — this is untrue. The second serious objection to this type of contraception concerns babies conceived accidentally when using rhythm methods. There is some evidence that such babies may be more likely than usual to suffer defects of the central nervous system, and that the incidences of ectopic pregnancy (implantation in the fallopian tubes) and placenta praevia (misplacement of the placenta in the uterus) are also increased.

These occurrences are more common because the babies are generally conceived when either the sperm or the ovum is at the end of its natural life-span and beginning to decay; consequently in some cases the pregnancy does not proceed normally. This is an important consideration for women who object to the IUD or the pill because they can damage mother or baby — so can the rhythm methods. Ectopic pregnancy still carries a risk of death to the mother, and two ectopic pregnancies can leave a woman permanently sterile, as well, of course, as meaning that the baby’s life cannot continue.

Other objections are less serious from an ethical point of view, but important nevertheless. One is the use of the word ‘natural’, as in ‘natural family planning’ or ‘natural birth control’. Certainly the rhythm methods make use of the woman’s natural cycle of fertile and infertile times — but there’s nothing natural about taking your temperature early every morning, or abstaining from sex within marriage. Wendy Cooper in The Fertile Years says: ‘It now seems absurd to insist that menstrual charts, basal temperatures, thermometers, and sex according to the calendar rather than desire, is somehow more natural than the pill which, after all, allows expression of natural feelings at a natural time.’

On this same point, Gavin Reid in Starting Out Together says: ‘Quite honestly, this sort of view is emotional rather than intelligent. God has put us in a world where there is food to eat and where there are chemicals to be extracted which have properties we can discover and put to use. I call this “natural”.’

Another objection to over-enthusiastic recommendation of rhythm methods is the emphasis that ardent proponents put on the value of abstinence. God does not require sexual abstinence from us in marriage; he has given us marriage so that we do not have to practise sexual abstinence, and in fact his word specifically teaches that we should not deny each other sexually within marriage. I’m not denying at all that the fellowship experienced by some couples in sharing this method of birth control can be valuable in deepening a relationship, but I do object strongly to the way that some enthusiasts seem to value abstinence more highly than sex:

‘When we wanted a child, and therefore had intercourse more frequently, the experience became not quite as fulfilling. In times when we don’t need the discipline [of abstinence], as for instance during the time of pregnancy where there is neither menstruation or ovulation, it is almost as if something is lacking.’ This is twisting out of recognition the picture of joyous, free, unstinting sexual fulfilment in marriage that the Bible gives. As Joyce Huggett says in Growing Into Love: ‘This method of family planning concertinas the joys of sexual intimacy into a very limited space of time; a restriction which is to be questioned if we really believe that sexual intercourse is a major means of conveying a special sense of belonging.’ She goes on to say: ‘The safe period involves a calculated human intervention directed at avoiding conception as much as any other method, so why not allow couples to avail themselves of a choice of contraceptive?’

Tim and Beverly La Haye see the rhythm method as being a sensible way of calculating when you do and don’t need to use other methods of contraception, and I would echo this view. To those who find barrier methods such as the sheath, cap or sponge a bit of a drag (and who doesn’t?), then being aware of your own fertile times can limit the number of days in a month when you need to use these methods. I’m not suggesting that no Christians use the rhythm methods of birth control. If both partners are agreed that this is the method they choose, then fair enough — what I have done is to point out that there are major flaws in this method from the Christian point of view, as there are with most other methods. But to claim that this is the only ‘Christian’ method of birth control, as some people do, is indefensible.

Practicalities of the Rhythm Method of Contraception

The basic principle behind all rhythm methods is the same: to abstain from sex during the time in her monthly cycle that a woman is most likely to conceive. Consequently, sperm and ovum never meet, and pregnancy will be avoided. There are various types of rhythm method which use different means of calculating the fertile time, with different degrees of success.

Several factors are relevant to all rhythm methods. The first is that women ovulate at only one time in their monthly cycle (occasionally two eggs are produced within twenty-four hours, which can lead to the conception of fraternal twins). As a result, sex should be safe after the ovum has had time to leave the body or has become ‘over-ripe’ and therefore impossible to fertilize. The second factor which needs to be built into the calculations is that ova can live for up to forty-eight hours before this point. The third factor is that sperm can survive for up to four days in the woman’s reproductive tract if conditions are favourable.