Catholic Medical Quarterly

The Journal of the Catholic Medical Association (UK)

Building knowledge. Building faith. Protecting the vulnerable.

Catholic Medical Quarterly Volume 62(4) November 2012

Faith in medicine

Is religion bad for Natural Family Planning?

Dr Adrian Treloar, MRCGP, MRCP, MRCPsych

photo of Married coupleIt is a privilege to write for this journal reflections on Natural Family Planning and the challenges of Humanae Vitae. This encyclical is, I believe a beautiful document whose primary definition of marriage services an image of hope and beauty that the 21st century is desperately missing. Humane Vitae stated that married love takes its origin from God, who "is love," The central message of Humanae Vitae is that married love is:-


  • Fully human
  • Involves a total giving of one to another. 
  • Is exclusive 
  • Is faithful
  • And is fecund (open to life) 

It’s from this that Pope Paul VI was “obliged once more to declare” the prohibition on the use of artificial contraceptives. So Humanae Vitae is in fact centrally based upon the Church’s vision of marriage and the family. Humanae Vitae recalled the words of Pope John XXIII who said "Human life is sacred—all men must recognize that fact… From its very inception it reveals the creating hand of God."

Paul VI then stated that artificial birth control would:

“open wide the way for marital infidelity and a general lowering of moral standards”. And he called for scientists to "considerably advance the welfare of marriage and the family and also peace of conscience, if by pooling their efforts they strive to elucidate more thoroughly the conditions favourable to a proper regulation of births." (28) It is supremely desirable, and this was also the mind of Pius XII, that medical science should by the study of natural rhythms succeed in determining a sufficiently secure basis for the chaste limitation of offspring.”

With hindsight, we see that Paul VI’s appeal led many good men and women to ably develop the science of NFP. As a result we now have an effective reliable method of chastely limiting family size which works and is better than many other methods. And, sadly, we see that artificial methods of contraception have indeed been associated with the devastation in family life, with divorce and with illegitimacy as Paul VI foresaw. 

Why is Humanae vitae and NFP rejected?

It may be that at the outset NFP seems harder than other artificial contraceptive methods. The data on divorce, family stability and NFP’s effectiveness are not in the public mind. But in truth, if we are honest, we must admit that at least in part, the rejection of Humanae Vitae has been a rejection and attack on the Church itself. NFP is associated with the Church and religion and arguments are therefore neutralised simply by describing them as religious. NFP has been frequently dismissed as Vatican Roulette. Catholics are more easily (unjustly) dismissed when their scientific arguments are seen to be associated with their faith even when the science is robust [2].

The need to make the science of NFP more robust 

It is easy to think that we should move NFP simply into a scientific enterprise that is divorced from faith or religion. It is hoped that, as a result, the association with the Church may be forgotten and thus NFP’s rejection be lessened. This is, I think, simplistic and wrong. While it is true that many who are not Catholic come to use NFP for many reasons, such as the avoidance of side effects and dissatisfaction with other techniques, that merely constitutes data that we should use to dismiss the prejudices against NFP. Most of all, we need really good scientific data on NFP and the ways in which it works effectively and the ways in which it supports marital fidelity and other psychological benefits. When we hear that there is an evidence base that couples who use NFP have increased sexual enjoyment, we can but wonder how on earth such things fail to make headlines? Could it be that facts fall victim to bigotry against the Church and her teachings? 

So we MUST build the science and epidemiological data on NFP. Paul VI called for this 45 years ago and there is much to do. In all honesty, while I find myself convinced of the data re NFP, the presentation of data is not always as robust as one would hope for. 

Can NFP be removed or distanced from religion?

As rational scientists, we are bound to combine our scientific curiosity with that which we believe and that which is revealed. Humanae Vitae is a classic example of how an argument based on Natural Law made good science years after that science was called for. But marriage is perhaps the most fundamental building block of society. We cannot remove the spiritual and philosophical from the individuals whom we serve. In helping couples who are entering marriage it would be wrong to simply cut out the spiritual and philosophical and to only give them scientific data. NFP is part of the Church’s vision of the beauty of marriage and we cannot hide that beauty from individuals. But neither can we hide good quality data from individuals. 

The answer?

We must also share the hope of married love, which is fully human, 100% committed, is exclusive, faithful and open to human life, which from its very inception reveals the creating hand of God.

The denigration of NFP on the basis of its religious connotations may in the end be a testament to its validity. But then again, to help individuals, it is rash (or even wrong) if we emphasise the religious with the result that the scientific data is ignored. So in all that we do, we must see, know and be literate in an excellent scientific evidence base. We must also share the hope of married love, which is fully human, 100% committed, is exclusive, faithful and open to human life, which from its very inception reveals the creating hand of God. That necessarily combines both the religious and the scientific messages of NFP. For doctors and nurses, in their daily work, it requires tact, care and inspiration, but absolutely not imposition.

And that is a beautiful message, and one which deserves to be wanted and popular with many.


  1. Pope Paul VI. (1968) Encyclical Letter Humanae Vitae.
  2. Treloar A, Hardie R. (2011) Are Catholic academics unintelligent or dangerous subversives? Catholic Medical Quarterly Volume 61:(May)