"If we had the power to eliminate just one misunderstood notion about breastfeeding, it would be the concept of foremilk and hindmilk!" write Cindy and Jana, Registered Nurses and International Board Certified Lactation Consultants (IBCLCs) who have assisted over 20,000 breastfeeding mothers.
Research clearly demonstrates that nursing mammals (human babies, too) receive milk near the end of most natural nursing sessions that is higher in fat content than milk at the beginning of that feeding. One biological reason for this is that early milk is the thirst quencher - baby can cue to nurse for just a few minutes to satisfy thirst, or comfort needs. Early milk is also power-packed in immunobodies and glyconutrients (the healthy sugars that kill cancer cells and feed the developing immune system) - super charging baby's immunity even when nursing briefly on-the-go. As breastfeeding continues, milk gradually becomes more and more dense in (healthy) fat content with each swallow baby takes. This beneficial fat feeds the cells of the rapidly developing brain and body. When baby is able to choose his/her time to breastfeed, because of this perfect set-up, s/he can get a quick snack for thirst and comfort and immunity, or s/he can get a full hearty meal that fills the tummy and feeds the brain.
This being said, there is no magic set amount of time from one mother to the next, one baby to the next, one nursing session to the next, or even one breast to the other, at which milk suddenly changes from 'foremilk' to 'hindmilk.' It is all just milk! Very gradually fat content increases. With each swallow baby takes, milk content shifts to meet baby's needs. When s/he is in control (and able to nurse effectively) baby is able to determine just the right amount of time to breastfeed to get just what s/he needs. This is why it is so vital to watch your baby, not the clock.
For one mother this may mean baby nurses on one breast for 30 minutes. For another mother baby may nurse each side for 20 minutes, or 15, or 10. Baby may nurse for 5 minutes, and come back 10 minutes later to nurse again. And again. Baby may nurse for longer periods of time at night than in the morning. One baby may nurse differently than his/her sibling did. Baby may nurse differently today than s/he did yesterday, and change week to week, due to his/her needs and also mom's hormone fluctuations. Milk content changes from one swallow to the next, from one baby to the next in the same mother, from one day to the next, and certainly from one mother to the next. In the midst of this beautiful dance of lactation and normal baby feeding, there is no 'foremilk / hindmilk imbalance' that occurs within any one individual mother's breasts.
When well meaning friends or ill-informed medical professionals tell nursing moms to "make sure your baby nurses long enough to get hindmilk" or "if your baby's poop is green, you have a foremilk/hindmilk imbalance" they are not dispersing information based in science, and this leads to mothers being troubled and thinking something is wrong. Many U.S. hospital postnatal rooms reinforce this myth by having mom record "how long baby breastfeeds on each side" on a chart that is reviewed by nursing staff. Breastfeeding moms wonder, "How long is 'long enough' for baby to get hindmilk?" "Should I only feed from one breast to try and help my baby gain?" Women want to do what they are being told by hospital staff, and begin to watch the clock instead of their baby -- the precise thing we should not be doing.
"A little knowledge can be a dangerous thing." writes Nancy Mohrbacher, author of the fantastic books, Breastfeeding Made Simple, and Working and Breastfeeding Made Simple, among others. "This has never been so true as in the ongoing debate about foremilk and hindmilk and their impact on breastfeeding. The misunderstandings around these concepts have caused anxiety, upset, and even led to breastfeeding problems and premature weaning."
Where did the foremilk / hindmilk imbalance myth arise from?
The foremilk / hindmilk imbalance idea was coined in a 1988 journal article * that reported the qualitative observations of a few mothers who breastfed by the clock, switching baby from one breast to the other after 10 minutes, even if baby was not finished nursing on that side. This is not something that is ever good to do as it does not allow baby to gradually control the amount of milk s/he takes in. The results from this one report have never been duplicated, and newer research calls its methods and conclusions into question. Many well versed in lactation science doubt there is even such a thing as a foremilk / hindmilk imbalance.
Myth-busting Lactation Facts:
There are not two distinct kinds of milk. That's right - 'foremilk' and 'hindmilk' (as commonly as the terms are used) do not actually exist. There is no magic moment when foremilk becomes hindmilk. As noted above, the increase in fat content is gradual, with the milk becoming fattier and fattier over time as the breast drains more fully.
It is the total milk consumed daily by baby—not 'hindmilk' alone—that determines baby’s weight gain. Whether babies breastfeed often for shorter periods, or go for hours between feedings and nurse for longer times, the total daily fat consumption does not vary significantly.
Early milk is not always low-fat. The reason for this is that at the fat content of 'foremilk' varies greatly depending on the daily breastfeeding pattern. If baby breastfeeds again soon after the last nursing, the early-consumed milk at that feeding may be higher in fat than the late-consumed milk at other feeding. The longer a baby goes between feedings, the more varied milk will be from beginning to end when baby breastfeeds next. If baby is nursing more often than every 2-3 hours (frequent breastfeeding is normal and healthy for many babies at many points of development) than baby will be consuming fattier milk from the start.
If your baby is nursing more often, s/he is consuming more 'foremilk' that is higher in fat than babies who breastfeed less often. In the end, whether baby nurses for loooong stretches and goes 2-3 hours between, or breastfeeds more frequently, for less time, it all evens out at the end of the day, and watching baby and his/her cues is crucial (Kent 2007). Breastfeed on cue, around the clock, and safely sleep by your baby so that cue nursing and dream-feeding at night is easy too. See also: Your Baby's Signs of Hunger
Mohrbacher re-emphasizes: "What’s most important to a baby’s weight gain and growth is the total volume of milk consumed every 24 hours. On average, babies consume about 750 mL of milk per day (Kent et al., 2006). As far as growth is concerned, it doesn’t matter if a baby takes 30 mL every hour or 95 mL every three hours, as long as he receives enough milk overall (Mohrbacher, 2010). In fact, researchers have found that whether babies practice the frequent feedings of traditional cultures or the longer intervals common in the West, they take about the same amount of milk each day (Hartmann, 2007) and get about the same amount of milk fat. Let’s simplify breastfeeding for the mothers we help and once and for all cross foremilk and hindmilk off our 'worry lists.'"
Pumped breastmilk does not look like other forms of processed milk (cow, goat, etc.) that we are accustomed to seeing in the store. Cow milk is made perfectly for baby cows, not humans, as it is different in composition for the mammal it is designed to feed, and it also does not appear this way directly from a mother cow to her calf. Instead, natural human milk has a thin and watery appearance, with a creamy fat layer that may or may not develop when milk sits in the fridge. This is normal, and it will vary from one pumping to the next, and from one breast to the other.
If you are breastfeeding on cue, around the clock, babywearing in the day and safely cosleeping at night to keep baby close, and still find yourself concerned about baby's consumption, take note of how your baby nurses rather than watching any clock. Is your baby swallowing? Is s/he relaxed and content after nursing? Do her little hands open up into a tiny 5-point starfish when she is full? Is he gaining weight over the course of weeks passing? Baby's behavior matters far more than timing, and when we watch our babies and tune into their cues, we allow them to lead the way. In situations where baby is not gaining weight, an IBCLC can do a weighted nursing session (before/after breastfeeding), check for latch and suckle techniques by baby, and also note if a tongue or lip tie is preventing effective milk consumption. Reach out to an experienced lactation consultant in your area, and join local La Leche League and mom's milk cafe groups near you.
What about Green Poop?
Baby’s first bowel movements are the black and tarry meconium that was in the gut at birth. As breastfeeding commences, around Day 3 of life on the outside, baby’s poop changes to 'transitional stools,' which have a dark greenish color. Around Day 5, baby's poop color shifts again to yellow. Its consistency while exclusively breastfed (that is, while nothing but human milk is consumed) may look like mustard or split pea soup - liquid with seedy bits in it. Even when baby’s poop is all liquid with no seeds, and any variation of yellow-orange-green-brown, this is also normal.
In general lots of milk consumption in the early months, means lots of poops, no matter their color or how liquid or seedy they are. After 2 months of age, it is normal for many babies to poop only once every 3-4 days. There is very little waste in human milk, and this does not mean that baby is not receiving enough. Before 6-8 weeks of age, if baby is not pooping daily, a weight check is justified to ensure baby is receiving adequate amounts of milk.
Baby's poop color is not reason to worry if baby seems well and is gaining weight. In her book, Baby Poop: What Your Pediatrician May Not Tell You, Dr. Linda Palmer reminds readers that green is the most common color of baby stools seen, and should not cause alarm. "Beyond the newborn stage, the first matter of order when seeing green is to determine whether baby has eaten some especially green food, including kiwi, spirulina, or green veggies. It's said that grape-flavored Pedialyte [and other grape or chocolate or dark flavored/dyed items] can turn baby poop a bright green. If a child is being given iron supplements, these can turn his stools a dark evergreen." Palmer continues, "[I]f it's not a food pigment, then...green is the digestive juice bile; the same stuff that, when properly digested, imparts the normal yellow to brown colorations of poop. When bile comes out green, it is because the stool has been rushed through baby's digestive system, and not hung around long enough to break down. The question to ask is why."
Causes of Green Poop:
1) Food dye, natural coloring, or flavoring in mom or baby's diet. This is the most common reason for green colorations of baby poop. In the majority of cases, something minor has shifted poop coloration for a few days.
2) A virus. When baby is ill, the body produces excess mucus that is swallowed by baby. This rushes poop through the digestive tract faster, and poop color may change for several weeks. Keep breastfeeding! It’s the best way to support baby's immune system in fighting the virus.
3) Antibiotics, which also cause stool to rush through baby's system.
4) Teething. When baby is teething large amounts of saliva are swallowed, entering and irritating the digestive tract, causing matter to rush through more quickly. Give baby plenty of teething options to make the process as painless as possible. See: Teething Solutions.
5) Abundant milk supply. If mom produces so much milk that baby receives mostly high-sugar/low-fat milk, it may overwhelm baby’s gut in the early weeks and cause watery or green stools. One way to change this is to simply pump for a few minutes before nursing, and use the pumped milk for your later freezer stash when milk supply regulates, and/or baby grows to be more effective at nursing, with a larger mouth and bigger stomach. We've also used this high-immunity pumped milk to turn into breastmilk popsicles for teething or toddler days. Doing this gets baby fattier milk from the start, and gradually decreases milk production when baby does not fully empty the breasts. Another form of reducing milk supply is block nursing (or block feeding).
6) Inability to breastfeed effectively. A health or anatomy issue (tongue tie, lip tie) may prevent baby from getting the milk s/he needs. See an IBCLC in person to determine if this is the case.
7) Sensitivity to a food or drug in mom's diet. There are certain foods (cow's milk, nuts, soy) that contain proteins that cannot be digested by newborn human babies, but pass easily through mom's milk when they are in her daily diet. This impacts all babies in their early life, but some much more than others. If you notice that your baby is agitated, "colicky," has gas or tummy pain, reflux, sometimes combined with frothy/green stools, it is very likely that your baby is responding more intensely to these items in your diet. Eliminating nuts and soy in the early months, and switching to vanilla rice milk (for example) instead of cow's milk, will help baby's digestion, discomfort, and pain in virtually all cases. For an easy-to-understand synthesis of the research on this, see Palmer's excellent book, Baby Matters: What Your Doctor May Not Tell You About Caring For Your Baby.
In conclusion, the foremilk/hindmilk myth is a misconception that is popular, but not based in lactation science. Breastfeed your baby on cue, around the clock, in a pattern that is baby-led (not clock-led). Find comfortable ways to babywear and sleep by your baby to make life easier for you, and to provide baby with round-the-clock access to the milk s/he needs. Provided s/he is gaining weight, wetting, and occasionally pooping (yellow, green, orange - lots of variations of normal), and is a happy and alert baby, all is well.
Aksit, Sadik, Nese Ozkayin, and Suat Caglayan. "Effect of Sucking Characteristics on Breast Milk Creamatocrit." Paediatr Perinat Epidemiol Paediatric and Perinatal Epidemiology, 16.4 (2002): 355-60.
Hartmann, P.E. (2007). "Mammary gland: Past, present, and future." in eds. Hale, T.W. & Hartmann, P.E. Hale and Hartmann's Textbook of Human Lactation. Amarillo, TX: Hale Publishing, pp. 3-16.
Kent, J. C. (2007). "How breastfeeding works." Journal of Midwifery & Women's Health, 52(6), 564-570.
Kent, J. C., Mitoulas, L. R., Cregan, M. D., Ramsay, D. T., Doherty, D. A., & Hartmann, P. E. (2006). "Volume and frequency of breastfeedings and fat content of breast milk throughout the day." Pediatrics, 117(3), e387-395.
Mohrbacher, N. Breastfeeding Answers Made Simple: A Guide for Helping Mothers. Amarillo, TX: Hale Publishing, 2010.
Mohrbacher, N. Breastfeeding Made Simple: Seven Natural Laws for Nursing Mothers.
New Harbinger Publications, 2nd Edition, 2010.
Palmer, L. Baby Poop: What Your Pediatrician May Not Tell You. Sunny Lane Press, 2015.
Palmer, L. Baby Matters: What Your Doctor May Not Tell You About Caring for Your Baby. Baby Reference, 3rd Edition, 2015.
* Woolridge MW and Fisher C. "Colic, 'overfeeding,' and symptoms of lactose malabsorption in the breast-fed baby: a possible artifact of feed management?" Lancet. 1988 Aug 13;2(8607):382-4.
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About the Author
Danelle Day focused on human labor and lactation sciences as part of her graduate work in human development. After ten years teaching at the university level, Day left full time academia to raise babies of her own, and joined Peaceful Parenting in 2006 as a clinical advisory board member where she has served thousands of breastfeeding families since that time.