Cue Feeding: Wisdom and Science
Lisa Marasco, BA, IBCLC, Santa Maria, California
Jan Barger, MA, RC, IBCLC, Wheaton, Illinois
from Breastfeeding Abstracts, May 1999, Volume 18, Number 4, pp. 28-29.
It is now commonly accepted that infants, most especially breastfed infants, thrive best when allowed to feed as they indicate their needs. Nevertheless, some mothers continue to believe that they must wait for their breasts to "fill up" between feedings in order to have enough milk for their babies, and some popular sources of advice for parents urge mothers to stick to a feeding schedule in which even young infants are fed at 3- to 4-hour intervals. Some infants may be able to thrive on scheduled feedings, but many others do not. Recent research on the breast's mechanisms for regulating milk production provides a better understanding of the importance of demand feeding and the role of infant appetite in the regulation of milk production.
Until recently, efforts to understand the processes that regulate milk synthesis have focused on the prolactin surge that occurs in response to infant suckling. However, researchers have not found a consistent relationship between plasma prolactin levels and maternal milk production. Taking a different approach, Peter Hartmann and his colleagues in Australia have studied human milk production by making topographical-type maps of lactating breasts before and after nursing sessions using video and computer equipment to assess changes in breast volume.4 The accuracy of this technique for measuring milk storage capacity and milk production has been assessed at ±5 percent. Based on this work, Hartmann has concluded that the rate of milk synthesis between feedings varies according to the degree of fullness of the breast; the fuller the breast, the slower the milk production rate, and conversely, the emptier the breast, the faster the rate at which the milk is replaced.
Hartmann and colleagues also quantified differences in the maximum storage capacity of women's breasts, identifying at least a 300 percent difference between women in their study. It was also noted that the women who had larger storage capacities often nursed at longer intervals, whereas women with smaller storage capacities nursed at more frequent intervals. Breast size was not always a good predictor of production or storage capacity, and all of the women had the ability to produce plenty of milk over 24 hours. What varied was the amount of milk that could be delivered at one feeding.
High prolactin levels are critical to the initiation of lactation, but as prolactin levels decline, endocrine control becomes less important to milk production, and autocrine systems take over.5, 6 However, successful long term lactation depends on the development of adequate prolactin receptors during the endocrine control period, which in turn appears to depend on the frequency of feedings: the more frequent the feeds, the greater the receptor development.3,8
We have found that many women experience success in schedule feeding their breastfed babies during the first couple of months. However, these women have an unusually high rate of milk supply failure around 3-4 months, as evidenced by babies who fall below acceptable growth standards, require supplementation, and/or who wean involuntarily, rejecting the slower-flowing, lower volume breast for a more copious milk supply in a bottle.
Research on feeding intervals and levels of fat in milk adds another dimension to the understanding of how infant appetite, as reflected in demand-feeding, regulates milk synthesis. Michael Woolridge has proposed that caloric intake at the breast, specifically fat intake, is responsible for infant appetite control and satiety. It is readily assumed that the mother of a baby who remains unsettled after feeding has inadequate milk volume. In reality, there may be a small but critical shortfall in her baby's fat or caloric intake.10 Proponents of scheduled feeds often place time restrictions upon how long babies should feed, thus limiting fat/caloric intake at the end of feeds.
Supporters of schedule/routine feedings believe that longer intervals make for hungrier babies who will demand more aggressively and who will obtain the higher fat milk available at the end of a feeding. However, Woolridge has shown that prefeed fat levels are inversely related to the length of the interfeed interval. Fat concentrations of milk can be maximized by increasing both feed frequency and the amount of milk removed from the breast at a feeding. When feed frequency and duration are restricted by predetermined feeding schedules, the result may well be lowered infant fat intake, symptoms of breast milk insufficiency, and underfeeding.2,10
A baby who is getting ready to feed displays cues even before he awakens. At first, baby may wiggle, toss and turn, or be restless in his sleep. If his hand is near his face, he may begin to root towards it and even attempt to suckle it or anything else near his mouth. If these early cues are ignored, the baby begins to "squeak" and fuss slightly and eventually works up to a full cry, expressing that he is now overdue for his needed nourishment. An experienced breastfeeding mother with baby nearby usually quickly discerns baby's needs and puts him to the breast early in this sequence of cues. For the mother who is scheduling her baby and/or sleeping apart from him, however, it is much different.7
A newborn who is left to cry for even a few minutes can become very disorganized and have a more difficult time latching on and sucking correctly. As a result he often does not take as much milk as he needs, and if this scenario is repeated, mother's milk production will decrease over time. This is yet another way in which feeding schedules can inhibit maternal milk production. In an attempt to prevent excessive crying, some proponents of infant schedules promote the use of pacifiers to delay feedings and/or eliminate non-nutritive sucking at the breast. Such interventions are not without risk. A recent study has documented that pacifier use is associated with a shorter duration of breastfeeding,1 while another study found that mothers who utilize pacifiers for their infants frequently exercise a higher degree of behavioral control while breastfeeding, often leading again to shorter duration of breastfeeding overall.9
Empirical and theoretical evidence combined continues to support current recommendations of the American Academy of Pediatrics11 that babies, most especially breastfed babies, need to be fed on cue and should be allowed to set their own routine, rather than placed on a predetermined schedule. It is our further conclusion that practices which interfere with babies' cuings have been responsible for low weight gains, failure to thrive, milk supply failure, involuntary early weaning, and possibly even some cases of colic, as well as infant regression and depression due to lack of parental responsiveness to baby's frantic cues. Maternal milk production and infant intake are influenced by many factors, including frequency of feeding during the establishment of lactation, maternal milk storage capacity, infant stomach capacity, milk fat content, and the degree of breast emptying at any given feeding. Thus the evidence is very strong that arbitrary scheduling of breastfed infant feedings is inadvisable for any mother who desires to breastfeed successfully.
Lisa Marasco is a La Leche League Leader and a lactation consultant in private practice in Santa Maria, CA. She is currently a Master's student at the Lactation Institute in Encino, CA.
Jan Barger is a clinical instructor and Program Director for Breastfeeding Support Consultants. She is a lactation consultant for a pediatric group in Wheaton, Illinois and has a private practice. She is also a past president of the International Lactation Consultant Association (ILCA).
1. Barros, F. C., C. G. Victora et al. Use of pacifiers is associated with decrease of breastfeeding duration. Pediatrics 1995; 95:497-99.
2. DeCarvalho, M. D. et al. Effect of frequent breastfeeding on early milk production and infant weight gain. Pediatrics 1983; 72:307-11.
3. De Coopman, J. Breastfeeding after pituitary resection: Support for a theory of autocrine control of milk supply? J Hum Lact 1993; 9(1):35-40.
4. Daly, S. E., J. C. Kent, D. Q. Huynh et al. The determination of short-term breast volume changes and the rate of synthesis of human milk using computerized breast measurement. Experimental Physiol 1992; 77:79-87.
5. Daly, S. E. and P. Hartmann. Infant demand and milk supply. Part 1: Infant demand and milk production in lactating women. J Hum Lact 1995; 11(1):21-26.
6. Daly, S. E. and P. Hartmann. Infant demand and milk supply. Part 2: The short-term control of milk synthesis in lactating women. J Hum Lact 1995; 11(1):27-37.
7. Neifert, M. Early assessment of the breastfeeding infant. Contempory Pediatr 1996; October, 2-16.
8. Perry, H. M. and L. S. Jacobs. Rabbit mammary prolactin receptors. J Biologic Chem 1978; 253:1560.
9. Victora, C. G., D. P. Behague, F. C. Barros et al. Pacifier use and short breastfeeding duration: Cause, consequence or coincidence. Pediatrics 1997; 99(3):445-453.
10. Woolridge, M. Baby controlled breastfeeding: Biocultural implications. In Breastfeeding: Biocultural Perspectives, ed. P. Stuart Macadam and K. A. Dettwyler. New York: De Gruyter, 1995.
11. American Academy of Pediatrics Work Group on Breastfeeding. Breastfeeding and the use of human milk. Pediatrics 1997; 100:1035-39.