One sided feedings or two?

Many mothers are now being advised to feed the baby on one breast at a feeding only.  Though the number who email me about breastfeeding problems varies from day to day, usually, on any given day about 1 in 4 of mothers experiencing breastfeeding problems are feeding the baby on just one breast at a feeding.  Even some who are supplementing with bottles and formula are offering the baby only one breast at each feeding and then giving the bottle.


This idea is presumably based on the information that the amount of fat in breastmilk increases as the baby drinks more milk from the breast, as this study International Breastfeeding Journal 2009;4:7-13, as well as several other studies suggest. This increase in fat as more milk is removed from the breast (by pumping) is likely to be true as well when the baby is on the breast and drinking. But this notion of feeding the baby on only one breast at each feeding, to follow a “rule”, has resulted in many mothers running into difficulty with late onset decreased milk supply.


Help with breastfeeding


To emphasize, this idea of milk increasing in the concentration of fat as more milk is released from the breast depends on the baby drinking, not just sucking without actually getting milk.  It is a myth, and important enough for me to repeat several times in these pages, that a baby is not necessarily getting milk simply because the baby is latched on and making sucking motions.


Video 1: This baby is drinking very well from the breast.  The pause in the chin as the baby opens to the widest, says “I just got a mouthful of milk”. The longer the pause, the more milk the baby received.


Video 2: This baby is latched on and sucking but hardly getting any milk from the breast. There is no pause in the chin because there is no milk flow.


Video 3: This baby is in between the other two babies in the above

videos, getting some milk but maybe not enough to gain weight

quickly.  Even with an improved latch and breast compression though,

the baby is drinking some, but not a lot.  It would be best if the

mother soon switched sides, before the baby starts to fall asleep

at the breast.  Please note, babies do not fall asleep at the breast

because breastfeeding is “hard work”.  This idea that babies fall asleep

at the breast because breastfeeding is “hard work” or that they burn

“too much energy” breastfeeding is just not true.  Babies fall asleep

when the flow of milk starts to slow, especially if they are only a few

weeks old. This mistaken idea of breastfeeding tiring out the baby

comes from the notion that “babies transfer milk”. No, it is

mothers who transfer milk


In other words, it is not a good idea to feed the baby on just one side, to follow a rule.  Yes, making sure the baby “finishes” the first side before offering the second can help treat poor weight gain or fussiness in the baby, but rules and breastfeeding do not go together well.  How does the mother know that the baby is “finished” the first side?  Because the baby does not drink much from the breast even with breast compression.


If the baby is not drinking, actually receiving milk from the breast, there is no point in just keeping the baby sucking without getting any milk for long periods of time.  It is best to “finish” one side and then offer the other.  The approach of feeding one side without “listening” to the baby ends up with a decrease in milk supply.


Many mothers will keep the baby on the first breast until the baby is completely asleep.  Thus, the baby may not take the second side even if offered it.  Let us imagine that the baby drank 80% of the milk he needed from the first side.  If he remains on the breast until fast asleep, he might not wake up to take the second side, not being particularly hungry at that point.  The baby should be offered the second breast when he is not drinking much any longer even with breast compression, not when he’s asleep.


Furthermore, babies tend to get less milk in the late afternoon and evening than in the morning, so what might work in the early morning (baby finishing the feeding with one breast only) may not work in the late afternoon or evening.  If the baby cries and fusses in the evening, the mother who has been advised “one breast/feeding” may keep putting the baby back to the same breast and finally conclude that she needs to give the baby a bottle of formula.  And surprise, surprise, the baby is satisfied, no longer fussy at the breast, no longer pulling at the breast, and sleeps 3 hours or even longer.  The mother may even be convinced that she does not produce enough milk. That evening bottle, if given regularly, is also likely to lead to decreased milk flow and as the milk supply continues to decrease, the problem may get worse and worse.  Even if the mother puts previously expressed milk into the evening bottle, that does not prevent the problem.


On top of that, what may work when the baby is a month of age, say, may not work when the baby is 3 or 4 months old. Yet, if the mother continues to believe that one breast at each feeding is best, the milk supply will continue to decrease, and many symptoms of late onset decreased milk supply may occur.  Which symptoms?


1. Decreased weight gain or even weight loss.  On the other hand, many babies will continue to gain weight reasonably well. This problem, usually, is the problem of the mother who started off with an abundant milk supply and often the milk supply is still fairly good. But the baby’s behaviour shows that something is wrong.  The real issue is not weight gain or whether the baby is getting enough milk, but the baby’s behaviour at the breast. The following 3 frequently made, but incorrect, diagnoses are demonstrated in the following video 4.


  • “colic” and general fussiness with the baby pulling at the breast, letting go of the breast and coming back to the breast and pulling off the breast again. As in this video.  Babies who cry a lot are usually crying a lot because they are hungry, not because they have “colic”.  And they may want more milk even if they are continuing to gain weight well.


  • reflux” with the baby pulling at the breast, letting go of the breast and coming back to the breast and pulling off the breast again. As in the video.  I believe that “reflux” is very uncommon in exclusively breastfed babies.


  • “allergy to something in the mother’s milk” with the baby pulling at the breast, letting go of the breast and coming back to the breast and pulling off again, and now including blood in the bowel movements. As in this video.


Video 4: This baby tries to latch on, but the latch is not particularly

good.  He sucks, gets small amounts of milk, but pulls off and on the

breast.  He is “gassy”, and not happy at the breast.  But despite the

almost universal belief that “gas” causes the baby to act like this or

that gas causes the baby to be fussy and “colicky”, gas causes none of this. 

This baby is acting like this due to late onset decreased milk supply and

one sided feedings.


  1. The baby starts to suck his fingers much of the time.  This is important because this may be the only other symptom associated with late onset decreased milk supply. So, the baby is generally happy, gains weight reasonably well, and sucks his finger much of the day. This is considered normal by many.  I don’t believe it is normal for the baby to suck his fingers much of the time.
  2. The baby starts to wake up frequently in the night when he previously woke up infrequently or not at all.  Or, surprisingly, perhaps, on the contrary, now sleeps long hours during the night, perhaps sucking his thumb or a pacifier.
  3. So-called “nursing strikes”, which I no longer believe are a real diagnosis.  The “nursing strike” is due to the baby’s sense that there is not much milk in the breast and therefore he loses interest in the breast and doesn’t latch on.  Interestingly the babies who refuse the breast in the day, often feed better at night, at a time when most mothers have more milk.
  4. Late onset sore nipples, with the baby “biting” or pulling at the breast.  As well, when flow of milk slows, babies tend to slip down on the nipple, causing the mother nipple pain.
  5. Candida/yeast/thrush does not explain the above symptoms though the mother is frequently told this is the problem. Babies are not generally bothered by thrush.
  6. Decrease in bowel movements.  This may be normal, but I am beginning to rethink this and believe that if breastfeeding is associated with any of the other symptoms listed here, infrequent bowel movements cannot be called “normal”.
  7. The baby may start waking up more at night.  This results in the baby getting more milk because, as mentioned already, babies tend to feed better in the night, and, as a result, this may be one reason that the baby continues to gain weight well in spite of other symptoms.
  8. On the other hand, the baby may start sleeping during the night when he wasn’t before, again a reaction to a decreased milk supply
  9. The baby is “self-weaning”. I do not believe a baby younger than 2 or 3 years of age will “self wean”.  If they lose interest in taking the breast, it usually means the mother’s milk supply has decreased.


How do we know the baby is “finished” the first side?


Because the baby is no longer drinking, even with breast compression. This does not mean the mother must take the baby off the breast as soon as the baby doesn’t drink at all for a minute or two (the mother may get another milk ejection reflex or letdown reflex). However, if it is obvious the baby is not drinking, we recommend the mother take the baby off the breast and offer the other side, before the baby is fast asleep.  If the baby is pulling at the breast and compressions are not helping, the mother should take the baby off the breast and offer the other side.  If the baby is awake and no longer hungry, he won’t take the second side.  If the baby wants more, the baby will take the second side.  If the baby becomes too sleepy while on the first breast, though, he may not take the second side.  How do you know the baby is drinking or not?


If the baby lets go of the breast on his own, does it mean that the baby has “finished” that side?  Not necessarily.  Babies often let go of the breast when the flow of milk slows temporarily, or sometimes when the mother gets a milk ejection reflex and the baby, surprised by the sudden rapid flow, pulls off.  The mother can try him again on that side if he wants more, but if the baby is obviously not drinking even with compression, she should switch sides.  Before he gets too sleepy because if the baby is fast asleep, he might not take the second side even though he would if he were more awake.


Need breastfeeding help?  Make an appointment with the International Breastfeeding Centre.


Copyright: Jack Newman, MD, FRCPC, 2017, 2018


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