Archive for September, 2020

Natural Family Planning and Catholic Moral Teaching

Sunday, September 27th, 2020

Your Right to Know: Catholic Moral Teaching Moral teaching in the NFP course.

It is well known to the general public that the Catholic Church teaches against the use of contraception. It is also common knowledge that most Catholics, at least in the Western world, ignore this teaching. Many may wonder why the Church continues to teach in this way, and I intend to address that more fully in a future blog. For the present I will say only that the Church cannot and will not change its teaching on love, marriage, and sexuality including birth control because (1) the Lord has created his Church as the “pillar and bulwark of truth” (1 Timothy 3:15) and (2) because marital contraception is intrinsically dishonest. That is, sexual intercourse is intended by God to be at least implicitly a renewal of the marriage covenant. It is supposed to be a bodily way of reaffirming the faith, the love, the commitment, the total self-gift and the better-and-for-worse of the marriage covenant. But the body language of marital contraception says “I take you for better but positively not for the imagined worse of possible pregnancy.” That contradicts the marriage covenant and makes it dishonest.

What needs to be taught in an NFP course? The NFP course cannot be a course in moral theology for at least two reasons—time constraints and also because many or most NFP teachers would feel quite inadequate in trying to teach moral theology. However, anyone teaching NFP can be expected to convey standard Catholic teaching relevant to NFP and sexuality.

God calls married couples to generosity in having children and raising them in the ways of the Lord. Marriage is for family. “Natural family planning” is not “Catholic birth control.”

•When couples have a sufficiently serious reason to avoid or postpone pregnancy, they may resort to the periodic abstinence of systematic natural family planning. To put it another way, couples do need a sufficiently serious reason to use systematic NFP for postponing or avoiding pregnancy. They certainly do not need a life or death situation as their reason, but they are called to be generous, not selfish.

•No such reason is needed for ecological breastfeeding. No mother can force her baby to nurse. A mother simply needs to want what is best for her child, follow the Seven Standards, and let nature take its course.

The “method” of systematic NFP is chaste abstinence from the marriage act during the fertile time. That excludes using contraceptive behaviors during the fertile time as well as at any other time. That excludes not only barrier methods but also masturbation (whether solitary or mutual) and sodomy whether oral or anal. Chaste abstinence does not mean that spouses have to live as brother and sister, but they are to avoid stimulating themselves into orgasm.

Whether Catholic or Protestant or an unbeliever, you have a right to know these teachings. When they are taught in the context of Christian discipleship, they make sense. I am not suggesting that it is easy to convey these teachings, especially those in the last paragraph above, but couples have a right to know them. Given the low level of purity even at the high school level in many areas, it is quite possible that any given person in the NFP class has already engaged in some of these immoral behaviors. When they hear “abstinence,” they may well think of one or more of these behaviors as a way to do “NFP” and avoid the difficulty of sexual self-control. They know that the NFP teacher knows about these behaviors, and if they hear nothing, they may well rationalize that silence means consent. I have had first-hand reports from people who did.

In my opinion, Catholic moral teaching in an NFP course needs to be placed in the context of Christian discipleship. When a person appreciates the love that the Lord Jesus has for us, and the price He paid, and that He truly did promise to keep the truth about love alive in His Church, then when His teaching about the daily cross is applied to marital love and sexuality, it all makes sense. This is what we have tried to do in Chapter 1 of our manual, Natural Family Planning: The Complete Approach at

John F. Kippley

Natural Family Planning and the Cervix Sign

Sunday, September 20th, 2020

Your Right to Know: The Cervix Sign

As indicated in the August 11 post of Dr. Edward F. Keefe’s COVERLINE article on the internal observations of cervical mucus, his patients taught him about changes in the cervix itself, changes that had not been previously reported in the medical literature. He first reported on this in 1962 in the Bulletin of the Sloane Hospital for Women. Fifteen years later he reported it in the International Review of Natural Family Planning, Vol.1, Number 1, Spring 1977. It is interesting both in its detail and in the responses he gives to questions about its effectiveness when used in systematic NFP.

As Dr. Keefe indicates in this article, squeamishness hinders some women from ever making the exam, and he addresses that issue. He never advocates a cervix-only system for purposes of avoiding pregnancy. In NFPI we teach the observation of the cervix as a supplement to the mucus and temperature signs. Experienced women have told us that the cervix sign is sometimes the best sign for them about their fertility or infertility, especially in extended breastfeeding amenorrhea or during premenopause.

If you would like to read his 1977 report, see

John F. Kippley

Natural Family Planning and the Temperature sign

Sunday, September 13th, 2020

Your Right to Know: The Temperature Sign

The temperature sign is an extremely valuable component of the science and art of natural family planning.

•An elevated temperature pattern provides a positive sign of being past ovulation.
•It provides a highly accurate way to determine both the beginning of the fertile time and the end of the fertile time.
•Twenty-one days of elevated temperatures provide a 99% degree of certainty that you have achieved pregnancy.
•It provides the single best predictor of the date of childbirth, and it takes only a few minutes to take one’s waking temperature.
•It can be used by itself, and it can also be used in a cross-checking way with the cervical mucus.

You have a God-given right to know all these God-given realities about the temperature sign.

Here’s a brief summary of how this information developed, and in what follows, Phase 1 = pre-ovulation infertility; Phase 2 = the fertile time; Phase 3 = post-ovulation infertility.

In 1877 Mary Putnam Jacobi found that a menstruating woman’s temperature rises about mid-cycle and remains elevated until the start of menstruation. She was a feminist of sorts, seeking to prove that menstruation was not a sickness that prevented women from working outside their homes.

A person of great interest to NFP history is Rev. Wilhelm Hillebrand, a German Catholic priest who had a scientific mind and simply wanted to help his parishioners. In the very early 1930s he was aware of the “rhythm” work of Dr. Kyusaku Ogino and Dr. Hermann Knaus and began advising couples according to the Knaus calendar-rhythm formula. Soon he had reports of three unplanned pregnancies. Then he remembered the temperature-based research of Dr. T. H. van de Velde reported in 1926.

In 1935 Fr. Hillebrand collected 76 temperature graphs from 21 women, and from this he invented the Calendar-Temperature method as it would be later called. In this system, a previous-cycle calculation such as “Shortest cycle minus 19” was used to determine the end of Phase 1, and Hillebrand’s genius was to insist that elevated temperatures were required to establish the beginning of post-ovulation infertility. He thus eliminated the weakest side of calendar rhythm. (The 19 Day Rule has since been changed to the 21 Day Rule and the 20 Day Rule.)

Over the years, various doctors contributed to our understanding of how to interpret temperature graphs for the start of Phase 3, and they also contributed to increasing the effectiveness of previous-cycle rules for the end of Phase 1. But there was nothing by way of published effectiveness data.

In 1967 Dr. G. K. Doering of Germany made a significant contribution to the science of natural family planning with his temperature-only study published shortly before Humanae Vitae. See the translation of his report at . Of great significance is that his “end-of-Phase 1” rule is based on the temperature pattern. This was unique because previous researchers had used an end-of-Phase-1 rule based on the length of the entire cycle such as “Shortest cycle minus 19.” Doering based his calculation on the first day of thermal shift in previous cycles, thus eliminating variations based on the length of the luteal phase (the days between ovulation and the start of the next menstruation).

In his study, Doering gives us statistics for two different groups— (1) those who engaged in the marriage act both in Phase 1 and in Phase 3, and (2) those who limited their marriage acts to Phase 3. In the first group, he found a 96.9 percent effectiveness rate that included all the marriage acts in what was clearly Phase 2. In the Phase 3-only group, the effectiveness rate was 99.2 percent. This was a temperature-only system with no cross-check from the disappearance of cervical mucus.

Dr. Konald Prem decided in the early 1970s that we could modify the Doering Phase 3 rule into a cross-checking sympto-thermal rule by requiring that that the three days of high-level temperatures must be cross-checked by a minimum of two days of mucus drying up to assure that the temperature rise is due to ovulation and not a cold or sickness. When this rule can be applied, it provides the earliest start of Phase 3 of any of the other STM or the mucus-only rules. In NFP International, we call this Rule K.

Konald Prem has also given us an accurate temperature-based rule for estimating the date of childbirth (EDC). The rule that doctors used almost universally previous to this time was the Naegele rule from the mid-19th century: start with the first day of the last menstrual period, add 1 year, subtract 3 months, and add 7 days—approximately 40 weeks. It works quite well when a woman ovulates about cycle day 14, but it is increasingly inaccurate when ovulation occurs a number of days after day 14, and it is worthless when a breastfeeding mother conceives before she has her first period.

The Prem rule uses the rise in post-ovulation temperatures. Take the first day of elevated post-ovulation temperatures, subtract 7 days and add 9 months. In a mid-Seventies article in a medical journal,he wrote that this is the most accurate way to predict the EDC, more accurate than much more elaborate and expensive procedures such as “estimation of uterine size by palpation or measurement, the dates of quickening and engagement of the fetal head and auscultation of the fetal heart tones with the head stethoscope…” or “biochemical and biophysical methods such as estriol, ultrasound and phospholipids…” (Konald A. Prem, “Assessment of Gestational Age,” Minnesota Medicine, September 1976, 623). For examples of how this knowledge has helped to avoid a premature induction of labor and to require an insurance company to cover the expenses of a premature baby, see page 70 of our manual, Natural Family Planning: The Complete Approach.

Breastfeeding mothers who conceived many months postpartum and before their first menstruation have expressed great gratitude for the Prem temperature-based rule.

Other benefits of recording temperatures are found when women experience breakthrough bleeding and irregular shedding. These are also described in our NFP manual. Among many married couples, a significant advantage of using the temperature sign is that it gets the husband involved, and this can be very helpful.

The weakness of the temperature sign is that when ovulation is significantly delayed, as happens during breastfeeding infertility and during premenopause, it does not signal the start of Phase 2. However, it does confirm continued non-pregnancy as long as the temperatures remain low. A second weakness, if it can be called that, is that it is so easy to take and record daily temperatures that some women ignore their mucus signs. I once heard Dr. John Billings cite this as a reason why he switched to a mucus-only system.

In NFP International we strongly recommend using both the mucus and the temperature in a cross-checking way.

We know that the elevated temperature reflects elevated levels of progesterone that is secreted by an ovarian follicle, the corpus luteum, after ovulation. I do not know why this hormone causes a woman’s waking temperature to rise, but it is a God-given reality.

And you have a God-given right to know these realities.

John F. Kippley