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Comparison of Ecological Breastfeeding with Lactational Amenorrhea Method

Sheila Kippley

God's Plan for Mother and Baby
I am grateful for the opportunity to speak about breastfeeding. A couple who uses breastfeeding to space their babies is using Natural Family Planning (NFP). I commend the organizers of this conference for wanting to examine the contribution breastfeeding has played NFP. Because this is a faith and science conference, I'd like to present some faith-based thoughts about breastfeeding and then offer the scientific aspects of breastfeeding with respect to natural infertility.

Breastfeeding and Church Teaching
Does the Catholic Church have any teaching on breastfeeding? Fr. William Virtue asked this very same question in the early 1990s, and his search culminated in the publication of his book, Mother and Infant. Fr. Virtue states that "the testimony of the Magisterium and moral experts confirms that it has been the constant teaching of the Church that there is a serious obligation of maternal nursing." (Virtue 1995, 278) That is so strange to our ears that I want to repeat Fr. Virtue's statement. "The testimony of the Magisterium and moral experts confirms that it has been the constant teaching of the Church that there is a serious obligation of maternal nursing." By serious, he doesn't mean "mortal sin serious," but he does mean serious and not just trivial.

Is there papal teaching on this subject?
According to Fr. Virtue, Pope Gregory the Great, Pope Benedict XIV and several saints taught the moral obligation for a mother to nurse her baby. (Virtue 1995, 272) The teachings of two recent Popes are better known. In 1941 Pius XII taught that the mother's influence and her education of the soul and body of her infant begin at the cradle. Thus Pius XII urged all mothers to breastfeed their babies, if at all possible. (Yzermans 1961, 44)

In May 1995, Pope John Paul II promoted the immunological, nutritional, and emotional benefits of breastfeeding. "This natural activity benefits the child and helps to create the closeness and maternal bonding so necessary for healthy child development." (J.P. II 1995, 14) The present Pope encouraged mothers "to breastfeed for 4-6 months from birth and to continue this practice, supplemented by other appropriate foods, up to the second year of life or beyond." (J.P. II 1995, 15) "No one," he says, "can substitute for the mother in this natural activity." (J.P. II 1995, 15)

Catholic Church Documents
When the Church speaks of Natural Family Planning in such encyclicals as The Gospel of Life and Humanae Vitae, such teaching applies also to breastfeeding. In both encyclicals, we are told to follow God's plan through His biological laws.

In The Gospel of Life, John Paul II writes as follows:

In Section 22: "There is a plan of God for life which must be respected."
In Section 42: "We are subject .to [the] biological laws." In Section 97: We are told to "respect the biological laws inscribed in our person."

In Humanae Vitae, Pope Paul VI tells us to obey the natural law (n 11), to consider the biological processes first (n 10), and to observe those laws inscribed on our very nature by the Most High God if we are to be happy (n 31)!

Breastfeeding is God's biological law.
Breastfeeding is essential for life. There are only two voluntary acts between two persons that are necessary for the continuation or survival of the human race: the marital act between husband and wife and the breastfeeding act between mother and child.

Breastfeeding is a continuation of the care the child received from his mother during pregnancy. The baby has merely switched positions. In Scripture we are reminded of this continuity of care in 2 Macabees 7:27 when a mother tells her son, "I carried you nine months in my womb and nursed you for three years." There are three conditions present during pregnancy as well as during the breastfeeding.

1) The exclusive nourishment provided by the mother's body to her baby during pregnancy is continued after birth as the mother's body continues to provide exclusive nourishment again through breastfeeding.

2) The baby continues to receive that much needed touch and close physical contact by the mother through breastfeeding that the baby received from his mother during pregnancy.

3) During both pregnancy and breastfeeding, the mother usually receives many months of amenorrhea. Nature intends the typical mother to receive more months of amenorrhea through breastfeeding than through pregnancy.

Natural Child Spacing
In Scripture there is a hint of natural child spacing. In Hosea 1:8 a mother weans her child first and then she conceives and bears a son.

In Humanae Vitae, I am reminded of breastfeeding when I read: "God has wisely arranged the natural laws and times of fertility so that successive births are naturally spaced (n 11).

In the 1960s as a young Catholic mother I was very interested in breastfeeding infertility. The Catholic obstetrician I saw for my first pregnancy said that no matter how I nursed my baby I would have a return of menstruation by 3 months. I nursed frequently day and night, and, like he said, I did have a return of menstruation by 3 months postpartum. I saw a different Catholic obstetrician with our second baby; this doctor promoted the temperature method. However knowing I wanted to nurse my baby, he gave me the exclusive breastfeeding rule. I was told to only breastfeed, not to offer the baby even water, and to call him when menstruation returned. Menstruation returned a year after childbirth.

Why the difference between the two babies? I nursed both babies frequently day and night. I had attended La Leche League meetings prior to and after the births of our first two babies. I knew what kind of nursing was required to keep up an ample milk supply.

I searched for any scientific evidence to determine the validity of the statement that breastfeeding spaces babies. As I looked into the research and into the changes of my mothering practices with our second baby, I began to realize that mothering practices do directly affect the amount of nursing that occurs at the breast.

The research papers I found, dated from the 1930s to the1970s, are not much different from the conclusions of current breastfeeding research that we have today (pre-seventies research is listed in the first editions of Breastfeeding and Natural Child Spacing published by Harper & Row in 1974 and Penguin in 1975). The research up through the 1960s focused on two main points:

1) suckling by the baby can inhibit the ovarian cycle of the mother after childbirth and

2) early supplementation causes an early return of fertility for the nursing mother.

I would like to compare a few old and new studies. In 1967 scientists stated the importance of suckling that is "applied periodically and at short intervals" for improved lactation. (Grosvenor 1967, 453) Today Dr. William Taylor concludes that the frequent number of suckling sessions per day and a short spacing between each nursing session is what counts for the continuance of postpartum amenorrhea. (Taylor 1999, 308)

In 1943, Dr. Paul Topkins concluded that during "the amenorrheic period of lactation, ovulation does not occur." (Topkins 1943, 57) In 1954, Dr. Thomas McKeown studied over 900 nursing mothers. In this study no mother conceived while exclusively breastfeeding and before they had their first period. (McKeown 1954, 826) Today the Lactational Amenorrhea Method stresses the importance of lactational amenorrhea and of exclusive breastfeeding in preventing conception. (Consensus 1988, 1204)

In 1968, the year of Humanae Vitae, Dr. T. J. Cronin concluded that "provided full breastfeeding is in progress and menstruation has not returned, ovulation does not happen before the end of the 10th postpartum week." (Cronin 1968, 424) This 1968 knowledge fits in well with the Bellagio Consensus of 1988 which states that any vaginal bleeding can be ignored for the first 56 days or first 8 weeks postpartum in determining the mother's fertility if the mother is exclusively breastfeeding. (Consensus 1988, 1204)

One doctor stands out above all the rest because of the duration of his research on breastfeeding and natural child spacing from the 1950s to the1970s. Dr. Otto Schaefer researched breastfeeding conception rates among the Canadian Eskimos for over twenty years and showed how breastfeeding can impact a nation as well as the individual family. He concluded that the small size of the traditional Eskimo family was due to prolonged lactation. From the mid-1950s to the mid-1960s, he recorded a 50% increase in the birthrate among the Eskimos due to the exposure of baby bottles at the trading posts. "The shorter the distance [to the trading posts], the more frequently they had children." (Schaefer 1971, 15-16) The older Eskimo women, 30-50 years of age, had conceived their babies 20-30 months after childbirth due to prolonged lactation, while the younger women under 30 year of age, were conceiving 2-4 months after childbirth due to bottlefeeding and shortened lactation. (Schaefer/Hildes 1971, 6)

My husband and I also decided to do some research. An extensive survey was placed in the first edition of our self-published book, Breastfeeding and Natural Child Spacing, beginning in June 1970. In our analysis, the first sign of bleeding or spotting, no matter how early, was counted as a first period. If amenorrhea was reestablished, we recorded amenorrhea only by the first bleeding. For statistical analysis, any response of 1.0 to 1.9 was recorded as l.0. We excluded any nursing mother who had an unusually long amenorrhea, such as 40 months or longer. In other words, our analysis was quite conservative.

The determination of what constituted ecological breastfeeding was set by six criteria. These six criteria are very similar to the Seven Standards for breastfeeding infertility that are used today:

No pacifiers used
No bottles used
No solids or liquids for first 5 months
No feeding schedule other than baby's
Presence of night feedings
Presence of lying-down nursing for naps and night feedings

In 1971 we had 112 nursing experiences from 72 American mothers. Of those, 29 nursing experiences from 22 mothers followed the ecological breastfeeding or natural mothering program. Those mothers averaged 14.6 months of amenorrhea. (Kippley 1972)

After collecting surveys for 15 years, we had over 1500 breastfeeding experiences. A data analysis computer program was developed and a student nurse was hired to work the summer of 1985 to enter the data into the computer. The surveys were not pre-selected. We stopped inputting the data when the additional surveys showed no differences. Of 286 surveys recorded, there were 98 nursing experiences that qualified as ecological breastfeeding using the same Six Criteria as in the first study. These ecologically breastfeeding American mothers averaged 14.5 months of amenorrhea-essentially the same as the 14.6 months in the 1971 study. (Kippley 1989, 107-116) We concluded that there is no question that American couples can and do experience extended breastfeeding amenorrhea and natural baby spacing provided they do the right kind of breastfeeding.

We tried to discover if there was any single one of the six criteria for ecological breastfeeding that by itself showed an even greater duration of amenorrhea, but we found none. (Kippley 1989, 111) What we have discovered over the years is that the elimination of any one of the practices usually brings an earlier return of fertility.

Ecological breastfeeding with its frequent and unrestricted suckling of the baby at the breast is nature's way of spacing babies. God in His Wisdom provides many benefits to the nursing mother and her baby, one being natural child spacing.

Today we talk about the Seven Standards to describe the type of breastfeeding that provides frequent and unrestricted suckling and thus a natural extended amenorrhea for the mother. (Kippley 1999, 2) Each of the Seven Standards is important in its contribution to natural infertility. These Seven Standards are as follows:

  1. Do exclusive breastfeeding for the first six months of life; don't use other liquids and solids.
  2. Pacify your baby at your breasts.
  3. Don't use bottles and pacifiers.
  4. Sleep with your baby for night feedings.
  5. Sleep with your baby for a daily-nap feeding.
  6. Nurse frequently day and night, and avoid schedules.
  7. Avoid any practice that restricts nursing or separates you from your baby.

What is the natural norm?
Here we are looking to the norm of nature and not to the sociological norm or the norm that society expects. Frequent and unrestricted nursing is the norm. Extended breastfeeding is nature's norm. Extended amenorrhea is nature's norm. To have a period return by three months postpartum is the exception, not the norm, by nature's standards.

What are the effects of various types of breastfeeding upon fertility?

Our first consideration is cultural or restricted nursing. This is the type of nursing that is common in the United States. Some like to call it restricted nursing, since they hope that eventually cultural nursing will be similar to ecological breastfeeding.

Restricted nursing occurs when the mother uses pacifiers, bottles, early supplementation, babysitters, and strict schedules. This type of nursing has been studied extensively. Let's look at a study that is the best in the sense that these mothers took their breastfeeding a little more seriously than in the other studies. These mothers nursed for a longer period of time, and this study had the highest rate of amenorrhea at 6 months postpartum. Of the 485 mothers who nursed their babies for at least one month after birth, 38% were in amenorrhea at 3 months postpartum, but only 9% of the original 485 nursing mothers were in amenorrhea at 6 months postpartum. Further, of the 485 who nursed for at least one month after childbirth, only 111 mothers or 23% were still nursing at 6 months. (Salber 1966, 351) In most studies involving restricted nursing, most weaning occurs during the first few months after childbirth.

Our second consideration is exclusive breastfeeding. Exclusive breastfeeding is where the mother offers only breast milk to her baby. The American Academy of Pediatrics (1997), UNICEF (1993, 1999) and the WHO (IFBAN 2001) all encourage mothers today to nurse exclusively for the first 6 months of life.

In 1988 a group of international experts met in Bellagio, Italy to review all the scientific literature about breastfeeding infertility. The conclusion of this group about breastfeeding infertility has become known as the Bellagio Consensus:

A woman who is fully or near fully breastfeeding during the first six months postpartum has a "more than 98% protection from pregnancy" if she remains in amenorrhea. In determining amenorrhea, any vaginal bleeding during the first 56 days can be ignored. (Consensus 1988, 1204)

The exclusive breastfeeding rule today is often called the Lactational Amenorrhea Method. The best study involving the exclusive breastfeeding rule occurred at Santiago, Chile and was reported in 1992. I say "best" because the number of those mothers still in amenorrhea at 6 months was greatest in this lactational amenorrhea study. Of the 422 nursing mothers studied, 56% were still in amenorrhea at 6 months postpartum. (Perez 1992, 970) During these six months postpartum, this study showed a 99.6% non-pregnancy rate for these exclusively breastfeeding mothers before menstruation occurred. (Perez 1992, 968)

More current studies dealing with the Lactational Amenorrhea Method have changed the definition of amenorrhea so that a certain amount of bleeding is allowed. (Labbok 1997, 329) The definition of exclusive breastfeeding has changed to allow an infant to take a slight amount of supplement to breast milk each week, the supplement increasing slightly at each month postpartum. (Labbok 1997, 329)

In these current studies of the Lactational Amenorrhea Method two rules were also added to the exclusive breastfeeding rule to encourage frequent nursing among the mothers and thus achieve results closer to the results of ecological breastfeeding. These rules are:

1) Night feedings should be given and
2) "Intervals between breastfeed should not exceed 4 hours during the day, and 6 hours at night." (Labbok 1997, 328)

Basically, current studies of the Lactational Amenorrhea Method often stress the importance of night feedings and "no long intervals between breastfeeding." (Hight-Laukaran 1997, 343; Peterson 2000, 225) These additional changes have produced mixed results. In 1997, 62% and, in 2000, 53% of the nursing mothers using the Lactational Amenorrhea Method were in amenorrhea at six months postpartum (Labbok 1997, 332; Peterson 2000, 225).

In my work over the last 35 years, I have always been aware that an early return of menstruation is common among mothers who do only exclusively breastfeeding. I used to tell parents to picture an "ecological breastfeeding" pie. There are seven pieces to the pie and exclusive breastfeeding is only one piece of the pie. Too frequently exclusively breastfeeding mothers are disappointed to experience menstruation at 3 or 4 months postpartum. It is for this reason that those who promote breastfeeding and the Lactational Amenorrhea Method or the exclusively breastfeeding rule for amenorrhea emphasize the importance of frequent suckling day and night so that more mothers will enjoy six months of amenorrhea with a 98-99% natural infertility rate.

For example, UNICEF says, "If a baby sucks very frequently at the breast (whenever the baby wants to, including at night), then the return of the mother's periods will be delayed for much longer." Again this organization says, "Breastfeeding gives a mother 98% protection against pregnancy for six months after giving birth-if her baby breastfeeds frequently, day and night, if the baby is not regularly given other food and drink, and if the mother's periods have not returned." (1993) Thus certain researchers and promoters of the exclusive breastfeeding rule are describing baby-care practices that approximate ecological breastfeeding in some respects.

The third consideration is ecological breastfeeding. Ecological breastfeeding is described by the Seven Standards. In our late 1980s study of the mothers who were involved in ecological breastfeeding, 93% were in amenorrhea when their babies were six months old. That compares with 9% with restricted nursing and 56% with exclusive breastfeeding. At 12 months, 56% of those ecologically breastfeeding were in amenorrhea. That's the same as the Lactational Amenorrhea Method at 6 months. At 18 months, 34% of the mothers doing ecological breastfeeding were still in amenorrhea. (Kippley 1989, 111)

Let's conclude with a practical example. Let's imagine that you have a hundred mothers who want to experience the natural amenorrhea and infertility that God has built into breastfeeding, what will you teach them?

If they follow a restricted nursing pattern, only 9% will still be in amenorrhea at six months postpartum.

If they follow the Lactational Amenorrhea Method or the exclusive breastfeeding rule, about 56% will be in amenorrhea at six months.

If they do ecological breastfeeding, 93% will be in amenorrhea at six months and will receive the natural infertility rate of 99% during the first six months postpartum. Furthermore, if they continue with ecological breastfeeding, they will have their first period, on the average, around 14 months postpartum, and a third will still be in amenorrhea at 18 months.

The only type of breastfeeding associated with extended natural infertility or natural child spacing is ecological breastfeeding. The best answer is to teach ecological breastfeeding to all new mothers-to-be so they will be fully informed.


American Academy of Pediatrics, "Breastfeeding and the Use of Human Milk" (Policy Statement), Pediatrics (December 1997) 100: 1035-1039.

Consensus Statement, "Breastfeeding as a Family Planning Method," The Lancet (November 19, 1988), 1204-1205.

Cronin, T. J., "Influence of Lactation Upon Ovulation," The Lancet (August 24, 1968), 422-424.

Grosvenor, C. E., Mena, F., and Schaefgen, D. A., "Effect of Nonsuckling Interval and Duration of Suckling on the Suckling-Induced Fall in Pituitary Prolactin Concentration in the Rat," Endocrinology (September 1967), 81: 449-453.

IBFAN, IBFAB Info (The International Baby Food Action Network newsletter), "WHO's Global Strategy for Infant and Child Feeding Settles Duration of Exclusive Breastfeeding, (November 2001), 3:2.

Kippley, S., Breastfeeding and Natural Child Spacing (1999), The Couple to Couple League Int., Cincinnati, Ohio; 212 pages.

Kippley, S. K. and J. F., "The Relationship Between Breastfeeding and Amenorrhea: Report of a Survey," Journal of the Nurses Association of the American College of Obstetricians and Gynecologists, (November-December 1972) 1: 15-21.

Kippley, S. K. and J. F., "The Spacing of Babies with Ecological Breastfeeding," International Review, (Spring/Summer 1989), 107-116.

McKeown, T., and Gibson, J. R., "A Note on Menstruation and Conception During Lactation," Journal of Obstetrics and Gynaecology, (British, December 1954), 61: 824-826.

Perez, A., Labbok, M. H., and Queenan, J. T., "Clinical Study of the Lactational Amenorrhea Method for Family Planning," The Lancet, (April 18, 1992) 339: 968-970.

Salber, E. J., Feinleib, M., and MacMahon, B, "The Duration of Postpartum Amenorrhea," American Journal of Epidemiology (1966) 82: 347-358.

Schaefer, Otto: "When the Eskimo Comes to Town," Nutrition Today (November-December 1971) 6: 8-16.

Schaefer, O., and Hildes, J. A., "Health of Igloolik Eskimos with Urbanization," Circumpolar Health Symposium presentation, Oulu, Finland, (June 1971), 15 pages.

Taylor, W., Vazquez-Geffroy, M., Samuels, S. J., and Taylor, D. M., "Continuously Recorded Suckling Behaviour and Its Effect on Lactational Amenorrhoea," Journal of Biosocial Science, (1999), 31: 289-310.

Topkins, P., "The Histologic Appearance of the Endometrium during Lactation Amenorrhea and Its Relationship to Ovarian Function," American Journal of Obstetrics and Gynecology (January 1943), 45: 48-58.

Pope John Paul II, "Breastfeeding: Science and Society," Pontificiae Academiae Scientiarum Documenta 28, (May 11-13, 1995). Or L'Osservatore Romano, "Breastfeeding Protects Against Disease and Creates Bond of Love," (May 24, 1995).

UNICEF, Facts for Life, "Breastfeeding," (1993).

UNICEF, "Breastfeeding: Foundation for a Healthy Future," (August 1999), 12 pages.

Virtue, Rev. William D., Mother and Infant, Pontifica Studiorum Universitas, Rome, (1995), 407 pages.

Yzermans, V. A., The Major Addresses of Pope Pius XII: Vol. 1 Selected Addresses (St. Paul: North Central Publishing, 1961), 44.

Presented at NFP Conference, "Integrating Faith and Science through Natural Family Planning" Marquette University; Milwaukee, Wisconsin. June 22, 2002.

Note: This talk and other talks at this NFP conference are provided in the book, Integrating Faith and Science through Natural Family Planning, and can be obtained by calling Marquette University Press at 800-847-9736.