When my husband and I started using Natural Family Planning 23 years ago, we didn't anticipate it becoming a way of life. When we married in 1977, no one discussed the morality of birth control options with us. Instead of asking for help, we just started using oral contraceptives – as many other Catholic couples were doing – and, when that proved unsatisfactory, moved on to barrier methods.

In the late 1970s, we stumbled across Margaret Nofziger's book, A Cooperative Method of Natural Birth Control. She explained in very straightforward terms the hormonal basis of modern methods of NFP, and she made using the method sound appealing. In the spirit of scientific curiosity, we bought a basal thermometer. We started recording my temperatures in a lab notebook left over from the days when we were both science majors. We have never looked back.

What happened to convince us that this was so much better? Initially it had a lot to do with the level of satisfaction we felt, physically and emotionally. The physical is rather obvious, but the emotional was an unexpected bonus. It turned out that making love without physical barriers between us meant making love without emotional barriers as well. It required a lot of trust in, and love for, each other that we had not had to exercise before.

Divorce rates among those who use natural family planning tend to be very low. I don't know if this is because NFP users are committed Catholics to begin with, or because the communication needed to use NFP successfully feeds those marriages. My experience and feeling is that it is a combination of commitment and communication that fosters happy marriages.

Unfortunately, in 1981 not much was known about the effects of nursing on fertility. We took a class in the sympto-thermal method – and while we found the class itself less helpful than we had hoped, it introduced us to the local NFP community. By 1984 when our second child was born, Dr. Evelyn Billings had published her book with Ann Westmore, The Billings Method, which gave a great deal more information about nursing and fertility.

In 1986 our third child was born. By now the impact of nursing on fertility had attracted the attention of the scientific community, and a study was begun on the return of fertility for nursing mothers. One of the study centers was at Georgetown University and I was fortunate to be recruited as a subject.

This study eventually resulted in the Lactational Amenorrhea Method (LAM) which allows nursing mothers to rely on the natural infertility of breastfeeding for the first six months after a baby is born, as long as they meet certain conditions.

Fundamentally, NFP is a method of observing the signs and symptoms of a woman's recurring fertility and infertility in order to act on this information to either avoid or achieve pregnancy. The two most popular methods are the cervical mucus method (popularly known as the Ovulation Method or OM) and the sympto-thermal method (STM). OM involves learning about and charting a woman's cervical mucus. STM includes information about cervical mucus, the basal body temperature, and secondary signs of fertility such as breast tenderness and mid-cycle pain.

NFP classes are classes in fertility awareness, not sex education. Many couples learn for the first time that the woman ovulates only once per cycle and that the egg, once released, will survive for less than 24 hours. Most are surprised to learn that sperm can survive for up to five days under the right conditions. Understanding how to pinpoint the days of maximum fertility can help couples conceive. For women avoiding pregnancy, the method can bring peace of mind. Many studies, however, have shown it to be as effective as artificial methods. Couples closely following the method are rarely surprised by an unexpected pregnancy, though of course it does happen occasionally.

The key difference between NFP and artificial contraception is not effectiveness but intention. Those who use NFP never deliberately intervene to shut down that power of fertility that is part of the gift spouses bestow on each other when they marry.

Abstinence is the biggest obstacle for many people. Most couples will need to abstain 10 to 12 days in every cycle. There is no question that this can be difficult, and that sometimes the difficulty leads to a decision to go ahead and have a baby. Periodic abstinence can remind spouses of their love and desire for each other, leading sometimes to a "honeymoon effect" when it finally ends.

Though much more is now understood about the return of fertility while nursing a baby, the decline of fertility in the perimenopausal years is still largely unexplored. The perimenopausal time requires an even deeper commitment on the part of the couple, because lack of solid information and the very individual response of each woman to her decreasing hormone levels can make it more challenging to identify her fertile times. With love and patience couples can go through this time gracefully.

The benefits of Natural Family Planning – self-knowledge, marital satisfaction, spiritual growth for both husband and wife – these make NFP unique. No one denies that unexpected pregnancies occasionally occur and that abstinence is sometimes difficult. But those who choose to live in accord with the Church's teaching on family planning and responsible parenthood find that their marriage and their families are a tremendous blessing, not only to themselves but to the friends and community surrounding them.

Doerflinger is a Natural Family Planning teacher for the Archdiocese of Washington.