July 31, 2018
By Katie Douglas
Editor’s Note: FACTS is celebrating National Breastfeeding Month by highlighting benefits of breastfeeding and its impact on fertility and family planning. This overview of lactational amenorrhea is the first of a series written by Katie Douglas, an intern with FACTS this summer. Next week we will discuss the many benefits of lactation on a woman’s health.
A Strong Start
The World Health Organization and the American Academy of Pediatrics (AAP) recommend that breastfeeding be the sole source of nutrition for the first 6 months of life, followed by the introduction of solid foods to complement continued breastfeeding for at least 12 months. Building on this strong start, research supports breastfeeding for as long as baby and mom desire because of proven health benefits for both.
Infants who breastfeed have stronger immune systems and less infections, asthma or allergies. Breastfeeding “promotes a unique and emotional connection between mother and baby”[i] and is associated with a 36% reduced risk for sudden infant death syndrome (SIDS).[ii] These are merely a few of the many benefits of breastfeeding. For a thorough treatment of this subject, we invite you to read the 2012 AAP policy statement, ‘Breastfeeding and the Use of Human Milk.’ Policy statements from other organizations can be found here.
Lactational Amenorrhea and Fertility
Women and couples have long been aware of the absence of menstruation (amenorrhea) caused by breastfeeding postpartum. This biological phenomenon was probably first articulated by Leonard Remfry in 1895. He noted that in cases of absolute amenorrhea during lactation, women had a 6% chance of pregnancy in the first six months postpartum. Since then, further research has expanded our knowledge of lactational amenorrhea, but many still reject the lactational amenorrhea method (LAM) as a sound and reliable approach to family planning. Some may insist on using a second method of contraception, unaware that typical combination hormonal contraceptives may actually increase fertility postpartum, by reducing lactation.[iii] In fact, depending on the characteristics and quality of their feeding techniques, couples can readily use LAM as a primary means of family planning in the postpartum period.
Multiple mechanisms contribute to the suppression of ovulation during lactation. Initially, suppression is likely related to a weaker response of the pituitary gland to GnRH stimulation. This results in a lower release of LH, or luteinizing hormone, which is required to prepare a follicle for ovulation.[iv] This restrained endocrine response does not typically last longer than about a month.[v] Further research indicates nursing women have normal LH release prior to the return of menses and ovulation.[vi] The mechanism leading to extended lactational amenorrhea is most likely related to elevated prolactin and the suckling stimulation at the breast.[vii] While not entirely understood, the action and force of suckling result in negative feedback to the brain to halt ovulation.[viii] This factor varies depending on the infant and nursing practices, and techniques can be taught to increase the strength or frequency of the baby’s suckling.
Ecological Breastfeeding and the 7 Standards
While these findings are encouraging for women hoping to extend their time of infertility during lactation, the practice known as ecological breastfeeding can prolong the period of lactational amenorrhea even more. This is likely due to the increased frequency and availability of suckling to the infant, which suppresses ovulation further in the mother. The seven standards for ecological breastfeeding[ix] were developed by John and Sheila Kippley and are as follows:
- Breastfeed exclusively for the first six months of life without use of other liquids or solids, not even water.
- Pacify or comfort your baby at your breasts.
- Do not use bottles or pacifiers.
- Sleep with your baby for night feedings.
- Sleep with your baby for a daily-nap feeding.
- Nurse frequently day and night, avoiding schedules.
- Avoid any practice that restricts nursing or separates you from your baby.ix
Ecological breastfeeding stresses the importance of suckling and the mother-infant connection. While these seven standards may be unattainable for many mothers, particularly those who intend to return to the workplace, they can be applied individually or as desired by a family. Using some of the guidelines for an extended period of time may potentially yield a prolonged delay in fertility.
An early study showed that mothers utilizing the seven standards of ecological breastfeeding can experience amenorrhea for an average of 14.6 months following delivery.x This is striking, compared to even the mean 11.6 months of amenorrhea experienced by women in the same study who breastfed exclusively from 4 months to 3 years postpartum. This investigation also concluded that through ecological breastfeeding, women can expect a 95% chance of infertility in the first year postpartum and amenorrhea for 12 to 16 months.[x] On the other hand, the likelihood of the return of ovulation increases markedly with a rigid feeding schedule, earlier introduction of liquid supplementation, and an earlier first separation between infant and mother.[xi]
Lactational Amenorrhea Around the Globe
LAM has been used extensively in indigenous populations and developing nations, where modern artificial contraception has not been widely used. These methods are culturally competent and acceptable in societies where mothers stay with their children throughout the day and night. In these populations, children typically suckle more often and until an older age compared to children in more developed societies.
In one case study of Gainj people in the highland of New Guinea, 28 mothers were followed throughout their nursing period. The average age of children at weaning was 38.6 months. During the nursing period, mothers often fed on demand and slept with their children, emulating the practices of ecological breastfeeding for at least the first year of life. The women in this case saw a mean 20.4 months without ovulatory menstruation during lactation. This highlights the usefulness of lactational amenorrhea in different cultures as a safe and legitimate form of family planning.[xii]
There is optimism for future extended use of lactational amenorrhea. In the UK, the Faculty of Sexual and Reproductive Healthcare noted in their clinical guidelines for contraception after pregnancy that if women are “less than 6 months postpartum, amenorrhoeic and fully breastfeeding, the lactational amenorrhoea method (LAM) is a highly effective method of contraception.”[xiii] In the future, we hope to see increased support for women who desire to use LAM to space pregnancies naturally, and greater acceptance of women who continue to use LAM successfully around the globe. This will require widespread education on the notable effectiveness of LAM, as well as further research into its mechanisms and adaptability.
Editor’s Note: This resource from the American Academy of Pediatrics features articles on the benefits of breastfeeding as well as helpful tips for successful breastfeeding, weaning, times of transition, and more.
Author Bio: Katie Douglas is a rising junior at the University of Illinois at Urbana-Champaign, where she studies Molecular & Cellular Biology. For the past year and a half, she has worked as a research assistant in the Nutrition and Cancer Epidemiology & Survivorship Lab on campus. We are delighted that Katie is working this summer as an intern for FACTS and for the Family Medicine Education Consortium (FMEC).
[i] “Aap-Reaffirms-Breastfeeding-Guidelines.” American Academy of Pediatrics, 27 Feb. 2012, www.aap.org/en-us/about-the-aap/aap-press-room/pages/aap-reaffirms-breastfeeding-guidelines.aspx.
[ii] “Breastfeeding and the Use of Human Milk.” Pediatrics, American Academy of Pediatrics, 1 Mar. 2012, pediatrics.aappublications.org/content/129/3/e827.full.
[iii] Short, R.V. “Breast Feeding.” Scientific American 250, no. 4 (1984): 35-41.
[iv] Diaz, S., H Cardenas, A Zepeda, A Brandeis, V Shciappacasse, P Miranda, M Seron-Ferre, HB Croxatto. “Luteinizing hormone pulsatile release and the length of lactational amenorrhoea.” Hum Reprod 10, no. 8 (1995): 1957-1961.
[v] Ryu, Kyungza, Kab Bum Huh, Bock Ja Byoun, Hyun Mo Kwak. “Studies on the Mechanism of Post-partum Amernorrhea: Pituitary Ovarian Axis during Post-partum Amenorrhea in Lactating Women.” Yonsei Med J 22, no. 2 (1981): 137-144.
[vi] Diaz, S., H Cardenas, A Zepeda, A Brandeis, V Shciappacasse, P Miranda, M Seron-Ferre, HB Croxatto. “Luteinizing hormone pulsatile release and the length of lactational amenorrhoea.” Hum Reprod 10, no. 8 (1995): 1957-1961.
[vii] Ryu, Kyungza, Kab Bum Huh, Bock Ja Byoun, Hyun Mo Kwak. “Studies on the Mechanism of Post-partum Amernorrhea: Pituitary Ovarian Axis during Post-partum Amenorrhea in Lactating Women.” Yonsei Med J 22, no. 2 (1981): 137-144.
[viii]McNeilly, Alan S., Clem C.K. Tay, Anna Glasier. “Physiological Mechanisms Underlying Lactational Amenorrhea.” Annals of the New York Academy of Science 709, no. (1994).
[x] Kippley, Sheila K. and John F. Kippley. “The Relation Between Breastfeeding and Amenorrhea: Report of a Survey.” JOGN Nursing 1, no. 4 (1972): 15-21.
[xi] Taylor, H. William, Robert E. Smith, Steven J. Samuels. “Post-partum Anovulation in Nursing Mothers.” Journal of Tropical Pediatrics 37 (1991): 286-292.
[xii] Wood, James W., Daina Lai, Patricia L. Johnson, Kenneth L. Campbell, Ila A. Maslar. “Lactation and Birth Spacing in Highland New Guinea.” J. biosoc. Sci., Suppl. 9 (1985): 159-173.
RESIDENTS and MEDICAL STUDENTS!
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