Written by: Jacqueline Kent, Ph.D. | Issue # 20 | 2013
- Breastfed infants control their milk intake to match their appetite and growth rate.
- Exclusively breastfed infants normally show a wide variety of breastfeeding patterns.
- Between one and three months of lactation, breastfed infants take fewer, faster, larger feeds, but their total daily milk intake is constant.
- Knowledge of the variability and expected changes in breastfeeding patterns can improve mothers’ confidence about their milk supply.
Parents need to have realistic expectations of their infant’s breastfeeding behaviour to support the decision to breastfeed and avoid unnecessary supplementation. A recent publication on a longitudinal study of infant breastfeeding patterns and breastmilk intake provides much-needed evidence to give parents and health professionals confidence that there is a wide variation in normal breastfeeding behaviour, and also to demonstrate the changes parents can expect during the exclusive breastfeeding period.
Despite exclusive breastfeeding being the optimal way of feeding an infant, the percentage of mothers who exclusively breastfeed drops from over 75% who initiate to less than 11% at six months, well short of the Healthy People 2010 initiative goal of 50% of infants being exclusively breastfed for six months (Thulier and Mercer, 2009). The most frequent reason given by mothers for ceasing exclusive breastfeeding is a perception of insufficient milk (Hauck et al., 2011). Mothers’ perceptions of their milk supply may be based on infant behaviour and whether that matches the expectations of the parents. If these expectations are based on the behaviour of formula-fed infants, then the expectations are likely to be unrealistic for a breastfed infant. If these expectations are not met, the mother may lose confidence in her breastfeeding. A loss of confidence is a major factor in the decision to cease breastfeeding or introduce supplementary feeds (Flores-Quijano et al., 2008).
Infant formula comes with instructions on how much and how often to feed an infant. Parents and caregivers may encourage an infant to finish each bottle of prepared formula. The formula does not contain leptin, which regulates food intake, while leptin is a component of breastmilk. The composition of formula thereby reduces the infant’s self-regulation of milk intake. In addition, the rate of gastric emptying for formula is slower than for breastmilk, leaving the infant feeling full for longer and therefore potentially decreasing the frequency of feeding compared to a breastfed infant. Moreover, breastmilk has a lower casein concentration and forms soft, easily digestible curds in the stomach, so the infant may be ready to feed again after a short interval. For these reasons, infant feeding patterns may differ between breastfeeding infants and those receiving formula. If a breastfed infant cues to feed again after a short interval, the mother may assume that her infant has not received enough breastmilk during the previous breastfeed and mistakenly perceive that she has insufficient breastmilk.
Parents need to know that breastfed infants have a wide range of feeding behaviour. This has been documented in a cross-sectional study of exclusively breastfed infants between one and six months old, published in Pediatrics (Kent et al., 2006). The data dispel any belief that breastfed infants follow the same patterns of breastfeeding behaviour as formula-fed infants. The breastfed infants, who were all growing normally, cued to feed between four and 13 times a day. Some of the infants (13%) only ever fed from one breast during each breastfeeding session, while 30% of the infants always fed from both breasts during each breastfeeding session. The remainder sometimes fed from one breast, sometimes fed from both breasts, and occasionally had a ‘cluster feed’, going back to the first breast after finishing feeding on the second breast. For a 24-hour period, mothers measured the milk intake of their infants by weighing their infants before and after each breastfeed, referred to as test-weighing. These data showed that rather than taking the same amount during each breastfeeding session, the infants consumed between 0 mL (the infant went to the breast and apparently suckled but removed no milk) and 240 mL. The infants who breastfed less frequently consumed more milk during each breastfeeding session than the infants who fed more frequently. However, this relationship does not result in all infants receiving the same amount of breastmilk. There is a wide range in the total amount of breastmilk consumed by normal, exclusively breastfeeding infants, ranging from 478 to 1356 mL. The data show that the total milk intake is independent of the feeding frequency.
Measurement of the fat content of milk samples collected from the mother before and after each test-weighing shows that breastfed infants feed to appetite and do not always ‘empty the container’. The fat content of the samples allowed the researchers to calculate the amount of milk available in the breast and the proportion of the available milk that was removed from each breast during each breastfeed. They determined that the infants removed, on average, only 67% of the available milk and normally only drained the breast once a day. In addition, they ascertained that the total daily fat intake of the infant ranged from 15 to 50 g. and was also independent of the breastfeeding frequency.
The results of this cross-sectional study serve to inform parents and health professionals that there is a wide range in normal breastfeeding behaviour and breastmilk intake and that breastfed infants do not need to conform to an average or to the feeding behaviour and intake of bottle-fed infants. However, mothers may be concerned if their infants breastfeed less often or more quickly than usual, or if their breasts feel softer and less full as lactation progresses.
The longitudinal study of breastfeeding behaviour published recently in Breastfeeding Medicine by the Hartmann Human Lactation Research Group (Kent et al., 2013) recorded breastfeeding patterns and milk intake for each breastfeeding session over two to five 24-hour periods between one month and six months of lactation. This study has provided the necessary evidence to show that at every age there is a wide range in the number of breastfeeds in a day, but on average the frequency decreases between one and three months, after which it stabilises.
There is also a wide range in the duration of each breastfeeding session at every age, but on average the duration decreases between one and six months. However, rest assured that the infant is simply becoming more efficient at suckling; the amount of breastmilk consumed during each feeding increases between one and three months. The result is that, for each infant, the total amount of breastmilk consumed remains constant during exclusive breastfeeding between one and six months. Manufacturers of infant formula might consider taking this information into consideration and revising their feeding tables.
It is normal for breastfeeding infants to feed at night, even at six months of age. However, Kent et al. show that while one-month-old infants need frequent feeding day and night, the longest interval between feedings increases between one and three months. This may be related to the demonstrated increase in the maximum milk intake during a feeding, which may be a reflection of the increasing stomach capacity of the infant.
Both of these studies will help to reassure parents that changes in their infant’s breastfeeding behaviour are normal and not an indication of insufficient milk supply. Instead, objective clinical indicators, such as infant weight gain based on the WHO’s breastfed infant growth charts, should be used to determine whether to supplement with infant formula.
Flores-Quijano ME, Cordova A, Contreras-Ramirez V, Farias-Hernandez L, Cruz TM, Casanueva E. (2008) Risk for postpartum depression, breastfeeding practices, and mammary gland permeability. J Hum Lact 24:50-57.
Hauck YL, Fenwick F, Dhaliwal SS, Butt J. (2011) A western Australian survey of breastfeeding initiation, prevalence and early cessation patterns. Matern Child Health J 15:260-268.
Kent JC, Hepworth AR, Sherriff JL, Cox DB, Mitoulas LR, Hartmann PE. (2013) Longitudinal changes in breastfeeding patterns from 1 to 6 months of lactation. Breastfeed Med 8:401-407.
Kent JC, Mitoulas LR, Cregan MD, Ramsay DT, Doherty DA, Hartmann PE. (2006) Volume and frequency of breastfeedings and fat content of breast milk throughout the day. Pediatrics 117:e387-395.
Thulier D & Mercer J (2009) Variables associated with breastfeeding duration. J Obstet Gynecol Neonatal Nurs 38:259-268.