The year 1986 saw two publications on breastfeeding and natural child spacing. Both researchers concluded that the most important factor for extended breastfeeding amenorrhea is night feeding associated with bed sharing between mother and baby.
In the 1990s Dr. William Taylor studied the frequency of breastfeeding and infertility and concluded that it is the short intervals between feedings that delays ovulation. Mothers who nursed with long feedings and long intervals between feedings tended to ovulate earlier. Those mothers who nursed frequently with shorter intervals between feedings were more likely to ovulate later. His 72 American mothers who tended to follow the more natural pattern of breastfeeding averaged 14 months of postpartum infertility.
In 1999, Dr. Taylor found that in one of his study groups, the “median waiting time to first menses was 12.8 months.” In this paper he drew this conclusion: “Stated positively, when babies (1) sleep with the mother, (2) are held close to the mother’s body, and (3) accompany her everywhere, the resulting easy access to the breast may be a causative factor in the ecology of breast-feeding’s contraceptive effect.”
However, sometimes not everything that is found in a study is published. In personal correspondence, Dr. Taylor gave us some further refined results regarding this study. He wrote: “When we eliminated [from our study results] mothers who returned to work outside the home, did not let their baby sleep with them at night, introduced solids before six months and nursed less than a median of 9 times a day in the first three months, we ended up with a group that might be said to follow the natural mothering norm. For these 55 mothers the median wait to their first menses was 15.9 months.”
Just as the reproductive cycle is at rest during pregnancy, the reproductive cycle is also at rest for a lengthy period of time during breastfeeding – if you take nature as the norm. Sheila remembers well her favorite physiology teacher in high school stressing that the end of the reproductive cycle is not childbirth but breastfeeding. Unfortunately, many nursing mothers have their menstruation return soon after childbirth. But if you take nature as the norm, having menstruation return early is the exception. Extended breastfeeding infertility is the norm.
Someone might ask “How many mothers become pregnant before their first period?” In 1895, basically a non-contraceptive time, this question was researched by Dr. Leonard Remfry who reported that 5.77 percent of the women in his study became pregnant before a first postpartum menstruation. In 1969 a similar rate of 5.4% was found in Rwanda. In 1971, Dr. Konald A. Prem, a professor of Obstetrics and Gynecology at the University of Minnesota, studied this question and found “only five percent” of his breastfeeding mothers became pregnant before a first menstruation. The studies of Dr. Remfry and Dr. Prem are available at the website of NFP International.
From July 19th to the evening of August 7th (NFP Awareness Week through World Breastfeeding Week) anyone can purchase the following printed books at a 40% discount at lulu:
Natural Family Planning: The Complete Approach (coil edition preferred for learners)
The Seven Standards of Ecological Breastfeeding: The Frequency Factor
Battle-Scarred: Justice Can Be Elusive
Breastfeeding and Natural Child Spacing