Natural Family Planning: Nature's Way - God's Way

39. Sympto-Thermal Methods of Natural Family Planning

"Sympto-thermal" methods involve charting symptoms of the fertile time, as well as waking temperature, and allow couples to seek or avoid conception (conception regulation). Changes in cervical mucus secretion are the most important fertile time symptom. Since 1951 1 have made evaluation of the temperature rise dependent on cessation of cervical mucus flow; my handbook (1965)(1),(2) and a later study (1968)(3) presented the first authentic sympto-thermal methodology - "sympto-thermal" methods then current merely noted symptoms and interpreted the temperature independently of them.

The woman must learn to recognize at the vaginal entrance (vulva) the various forms of cervical mucus; she gradually develops a nuanced appreciation of the mucus symptom if she receives repeated instruction or herself studies a suitable handbook. With today's improved pedagogical techniques almost 100% of fertile women can successfully recognize both the increased fertile time cervical mucus secretion and its various forms ("more fertile type" and "less fertile type").

I consider only those elevated temperature readings significant for defining infertility which lie after cessation of that form of cervical mucus secretion which indicates the woman's particularly fertile time. A very simple rule ("after cessation of this cervical mucus flow watch for 3 'higher' temperature readings which are higher than the preceding 6 lower readings") identifies onset of a period of absolute infertility continuing into the beginning of the following cycle-the Pearl Index is "zero" (no pregnancies per 100 couples per year of use).(4)

A combined approach is used to determine early cycle infertility. The beginner may assume Days 1-6 infertile (Day I = the first day of "true menstruation"); the experienced woman may consider additional days infertile by attending to fine points of mucus observation or self-examination of the external cervical os. The probability of pregnancy from intercourse on or before Day 6 is less than I to 6,000 - Pearl Index 0.2 (better than the Pill), Use of both pre-and post-menstrual infertile days by 491 women in 17,026 cycles (4) yielded in practice an overall Pearl Index of 0.8 (as reliable as the Pill, but without its harmful and sometimes even lethal side effects (5).

Footnote: These results were obtained from couples of differing socioeconomic backgrounds, some of them with only primary school education. In contrast with clients of some other studies, these couples were not canvassed by a researcher but came of their own accord to my advisory service to learn NFP. The motivation was already there. Perhaps the teaching method enhanced motivation. This will help explain why among these clients we have an unplanned pregnancy rate of only 0.8 per 100 women years, whereas in some of the funded studies the rate may be as high as 20 or more. Another reason for differences in results among various studies of NFP is that even within what is called "the sympto-thermal method" there are in fact several approaches, of varying effectiveness. The principal differences concern the interpretation of the rise in temperature, and the determination of the post-menstrual infertile period.

by Josef Roetzer, M.D.

Josef Roetzer, M.D. former lecturer in Pastoral Medicine at the Universities of Innsbruck (Austria) and Regensburg (Germany) and at the Philosophical-Theological Universities of Linz and St. Poelten (Austria). Director of Marriage Advisory Service, A 4840 Voecklabruck (Austria), Vorstadt 6.


Next Page: 40. Programs in Latin America
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58