Do natural methods for fertility regulation increase the risks of genetic errors?

Genetic errors of many kinds are connected with the reproductive processes and are favored by a nunber of largely uncontrollable, endogenous, and/or exogenous factors. For a long time human beings have taken into their own hands the control of this process. The regulation of fertility is clearly a forceful request to any family, to any community, were it only to lower the level of the consequences of genetic errors. In connection with this request, and in the context of the Congress for the Family of Africa and Europe (Catholic University, January 1981), 1 question must still be raised and possibly answered. The question is: do or can the so called "natural methods" for the regulation of fertility increase the risks of genetic errors with their generally dramatic effects on families and on communities. It is important to try to give as far as possible a scientifically based answer to this question. Fr. Haring, a moral theologian, citing scientific evidence finds it shocking that the rhythm method, so strongly and recently endorsed again by Church authorities, should be classified among the means of "birth control" by way of spontaneous abortion or at least by spontaneous loss of a large number of zygotes which, due to the concrete application of the rhythm method, lack of necessary vitality for survival. He goes on to state that the scientific research provides overwhelming evidence that the rhythm method in its traditional form is responsible for a disproportionate waste of zygotes and a disproportionate frequency of spontaneous abortions and a defective childern. Professor Hilgers, a reproductive physiologist, takes on opposite view, maintaining that the hypotheses are arbitrary and the alarm false. The strongest evidence upon which Fr. Haring bases his moral principles about the use of the natural methods of fertility regulation is a paper by Guerrero and Rojos (1975). These authors examined, retrospectively, the success of 965 pregnancies which occurred in women who were using the temperature method for family planning and who had recorded the menstrual day of insemination, and they concluded that their results suggested that aging of human spermatozoa in the female genital tract is associated with a increased frequency of spontaneous abortions and that postovulatory aging of human ova results in postimplatation. Their results and conclusions were accepted with great caution by the scientific community. The kind of evidence which suggests that the use of natural methods may increase, in particular cases, the loss of embryos or fetuses, stimulates further research, but it seems a very weak basis for the establishment of principles of human behavior. At the present stage of knowledge the natural methods for the regulation of fertility cannot be qualified as methods which necessarily and considerably increase the risks of abortion of malformed progeny.