In 1943, Dr. Paul Topkins concluded that during “the amenorrheic period of lactation, ovulation does not occur.” Generally speaking, Dr. Topkins is correct since he did endometrial biopsies on 28 lactating mothers during amenorrhea repeatedly, mostly during the early months after childbirth. But today we know that mothers can experience ovulation during amenorrhea, especially when the nursing is not frequent enough and there are long intervals between the feeding sessions.
In 1954, Dr. Thomas McKeown studied over 900 nursing mothers. In his study, no mother conceived while exclusively breastfeeding and before they had their first period.
Today the Lactational Amenorrhea Method has been studied scientifically many times. This method provides an exclusively breastfeeding non-cycling mother with a baby under six months old with an effectiveness of at least 98%. Once the baby turns six months old or the mother quits breastfeeding exclusively or the mother begins to have vaginal bleeding or menstruation after the 56th postpartum day, this effectiveness no longer applies. This exclusive breastfeeding rule is promoted throughout the world.
Research since the 50s have shown that introduction of other liquids and solids during the early months after childbirth is associated with an early return of fertility. However, if a mother is interested in natural child spacing, she should exclusively breastfeed her baby for the first six months and also follow the Seven Standards of Ecological Breastfeeding.
Sheila Kippley
The Seven Standards of Ecological Breastfeeding: The Frequency Factor