Baby will only feed from one breast

Lopsided! What can I do? •

…When baby prefers one side, or when supply or breast size is greater on one side

By Kelly Bonyata, BS, IBCLC

  • Is this a problem?
  • Why does it happen?
  • Evening things up
  • Persuading baby to nurse better on the less preferred side
  • Will baby get enough milk?

Is this a problem?

Most women notice differences in milk supply, pumping output, milk flow and/or size between breasts. As with many other things (foot size, ring size, eyesight, etc.) asymmetry is normal in humans. In some women the difference between breasts is hardly noticeable; in others it is very noticeable. There is every variation in between. This is not usually a problem in terms of the breastfeeding relationship, so you certainly don’t need to do anything about it if the asymmetry does not bother you or baby; however some mothers prefer to even things out, particularly if there is a very noticable difference in breast size.

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Sometimes babies will refuse or fuss at a breast when the let-down is slower or too forceful, or the supply a bit lower. They in turn will prefer the side which lets down more/less quickly and in which the supply is more bountiful.

Why does it happen?

Possible reasons for variations in supply/milk flow between breasts:

  • Normal anatomical differences. All women have one breast that has more working ducts and alveoli than the other (usually the left side, though either is normal). Some women also have differences between the two areola/nipples (inverted, flat, different shape/size) which make it easier for baby to latch on to one side than the other.
  • Baby’s preference for one side. Most babies have a side preference to some extent. From the start, your baby may feel more comfortable being held on one side and therefore nurse it more efficiently and/or more frequently.
  • Mother’s preference for one side. Mom (consciously or subconsciously) may offer one side more than the other because she feels more comfortable nursing on that side.
  • Breast surgery or injury. If one breast was ever operated on or injured in any way, supply and/or milk flow can be affected.

If your newborn is refusing one side, have her doctor do a good physical exam to check for birth injuries. Some babies will have an injury that goes unnoticed at birth, but causes baby discomfort when in certain nursing positions.

If baby suddenly begins to refuse one side, it could be caused by an ear infection or other illness in baby (making nursing painful or uncomfortable on that side), an injury to baby (or something else, such as a sore immunization site) that makes nursing painful in that position, or a breast infection in that breast (which can make the milk taste salty). Many babies who refuse one side do so because mom has a much faster or slower letdown on one side (baby might prefer either the faster or slower flow). If all other possible causes are ruled out and baby continues to refuse one side, then consider seeing your doctor just to rule out any breast problems.

Evening things up

It is fine to just do nothing, but if the lopsidedness is bothering you, you can try to increase milk supply on the smaller side to increase the supply/breast size/milk flow on that side. Be careful, though, not to neglect the larger producing breast too much and allow too much backup of milk in that breast, because that may make you vulnerable to plugged ducts and mastitis.

Here are some things that can help to even things up (you don’t need to do them all; start off with the one thing that looks most workable for you):

  • Start baby on the smaller side for each feeding for a few days (baby usually nurses more vigorously on the first breast offered).
  • Nurse on the smaller side twice as often. For instance if you nurse on one side per feeding, you might nurse on the small side for two feedings, the larger side for one, then back to the smaller side for the next two feedings, etc.
  • Pump the smaller side for 5-10 minutes after some feedings.
  • Add an extra pumping session (for 10-20 minutes – smaller side only) in between feedings.

If the larger side becomes overfull, express just enough milk to relieve the pressure. Most mothers notice an “evening out” of some proportion within 3-5 days of doing these things. Most moms use these measures for a short time only, until they get the desired results, but others continue long-term.

There may always be a small degree of difference in breast size – at least to your own eyes. If there is an obvious difference in appearance through your clothing, you may want want to use nursing pads to give a more even appearance. Usually a difference in size is much more noticeable to you than to anyone else.

Persuading baby to nurse better on the less preferred side

  • Try starting your baby on the preferred breast and then once let-down occurs, slide her over to the other side without changing the position of her body. For example, start her in the cradle position and then slide her over into the football position.
  • Continue to try different nursing positions.
  • Offer this breast to your baby when she is just waking up but not fully awake or already a little sleepy. She is more likely to instinctively nurse at this time.
  • Nurse in a darkened and quiet room.
  • Offer this side with motion; i.e. walk, sway, bounce, rock, etc. until your baby starts
    nursing well.
  • If let-down on the less preferred side is too fast or slow, follow the suggestions in Let-down Reflex: Too slow? or Forceful Let-down Reflex
  • If supply on the less preferred side is low, follow the suggestions above and in Increasing low milk supply.
  • If baby seems to want a faster flow from the less preferred side, then try doing breast compressions to speed the flow.
  • See the suggestions in Help — My Baby Won’t Nurse!
  • Patience and persistence are key. Keep trying, and praise baby when she nurses well. Most of the time a baby will take the less-preferred breast with time. If baby is refusing or nursing rarely on one side, you may need to pump this side as often as the baby is nursing the other side in order to better maintain your milk supply.

Will baby get enough milk?

Yes – your baby can get all that she needs as long as she is allowed to nurse as often as she wishes – even if you nurse exclusively on only one side. If there is simply a difference in supply between breasts, baby will adjust her nursing to compensate. Overall milk production is generally not a concern unless other factors are involved.

If baby is completely refusing one side, you’ll want to pump that side as often as she nurses to maintain supply until you get her back nursing on that side.

If all else fails, one-sided nursing is very possible as long as your baby is allowed to
nurse without restriction. The side that you are not nursing on, once allowed to “dry up,” will be smaller than the other side. This will result in some degree of lopsidedness (though it may not be obvious), but this will remedy itself once weaning occurs.

Feeding from one breast - BabyCentre UK

In this article

  • I find it easier to breastfeed on one side. Is this normal?
  • What can I do if my baby has a favourite breast?
  • What position is best for feeding from both sides?
  • Will I look lopsided if I feed from one breast?
  • Why is my baby suddenly rejecting one breast?

I find it easier to breastfeed on one side. Is this normal?

Yes. This may be because it’s more comfortable for you, or because your baby latches on more easily to one breast than the other.

Sometimes, the letdown sensation is much stronger and more uncomfortable in one breast than the other. This may lead you to favour one side.

Letdown discomfort is normal. It should only last a few moments, and will lessen the more you feed.

However, if you feel pain or discomfort beyond the initial letdown, in either breast or both breasts, ask your midwife or health visitor to refer you to a breastfeeding counsellor or consultant. You may also be able to find a children’s centre near you where you can ask about breastfeeding support.

Many mums find it easier to latch their baby onto one breast than the other, maybe depending on whether they’re right or left-handed. But you will soon get the knack of feeding from both sides.

Some women only have one breast that produces milk, perhaps because they have had breast surgery. Whatever the reason, there is no problem with feeding a baby just from one breast, as there will always be enough milk (UKMI 2014). After all, most mums of twins or more find that one breast per baby works fine.

What can I do if my baby has a favourite breast?

If your baby is under six weeks old, you need to give yourself a chance to keep up a good supply of milk in both breasts. Your body makes milk on demand, so your milk supply may slow down in the less-favoured breast (NHS 2016).

To encourage your baby to take her less favoured breast, start feeds on that side. If that doesn't work, start her on her favourite side, and then slide her over to the other breast when your milk has let down (Bonyata 2016).

To build up your supply in the less popular breast, you could express from that side straight after your baby's finished feeding from her favourite breast.

If you're dexterous enough, you could express milk from one breast, while your baby feeds from the side she likes. This way, you are working with your natural letdown reflex.

Once your milk supply gets going in the less-favoured side, try to gently encourage your baby to swap over. It’s best to wait until she’s already had a little feed. If she is very hungry, the change may just make her frustrated.

If your baby is always allowed to finish the first breast, it may be that this is all she needs, particularly in the early days. If she always seems full after feeding from one side, just offer the other breast first, the next time she asks to feed.

Even if the favourite breast does end up contributing more and more to a feed, it won't matter to your baby. The important thing is that your baby is getting enough milk, and is putting on weight.

What position is best for feeding from both sides?

You could try laid-back breastfeeding, especially while you’re getting the hang of breastfeeding.

This encourages your baby’s natural reflexes to find your breasts. As a breastfeeding position, it relies less on sides, because your baby lies on your tummy or chest, while you rest back supported by pillows or cushions.

You could try different positions for each breast, using the same hand to bring your baby to your breast on either side. You could hold your baby underarm to feed from one breast, and across your body for the other.

This may help if your baby likes lying on one side, perhaps from being in a certain position in your womb, or a muscle tightening on one side of her neck (torticollis).

If there’s a big difference in the texture or size of your nipples, your baby may find it easier to latch on to one than the other. This will matter less as you and your baby become more experienced at breastfeeding.

In time, you'll probably find yourself helping your baby to latch on without even thinking about it. Then you can feed in any position you like.

Will I look lopsided if I feed from one breast?

It’s unlikely that anyone will notice any difference. You may be very aware of it in the early days but, as time goes by, any imbalance should even out.

Even if you are still breastfeeding, your breasts naturally reduce in size between six months and nine months after your baby is born. They will still produce about the same amount of milk (Kent 2007). The amount of milk your breasts can store adapts to meet your baby’s needs (Kent et al 2006).

Breasts go back to more or less their original size after 15 months of breastfeeding, or after you have weaned your baby (Kent 2007).

Why is my baby suddenly rejecting one breast?

If your baby suddenly turns away from one breast, try to work out why it’s happening. She may have a blocked nostril or an ear infection that means she prefers one breast (Bonyata 2016).

If you have mastitis, she may not be keen on the milk from your affected breast, as it can make milk taste salty (Bonyata 2016). Try to keep feeding from your affected breast, though. It's quite safe for your baby and will help to treat the mastitis.

In both of these cases, get help from your health visitor or doctor so they can help your baby and you to recover.

When your baby's older, a low milk supply, or a reduced flow of milk in one breast, may make her favour the other breast. It’s common for one breast to produce more milk than the other (Kent et al 2006).

If you can’t work out why your baby is rejecting one breast, check how she is latching on. Try changing her position when she breastfeeds.

Your baby may have grown too big for the position you’ve both become used to. Sometimes just sitting your baby up more, if she’s been lying across your lap, is all you need to do.

Watch a video showing you different breastfeeding positions.


Bonyata K. 2016. Lopsided! What can I do? [Accessed March 2017]

Kent J, Mitoulas L, Cregan M, et al. 2006. Volume and frequency of breastfeedings and fat content of breast milk thoughout the day. Pediatrics 117(3):e387-95 [Accessed April 2017]

Kent J. 2007. How breastfeeding works. J Midwifery & Women’s Health 52(6): 564-70.

NHS. 2016. Breastfeeding: Is my baby getting enough milk? NHS Choices, Health A-Z. [Accessed April 2017]

UKMI. 2014. Q&A 73.5 Drug treatment of inadequate lactation. UK Medicines Information. [Accessed April 2017]

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What to do if the baby takes only one breast - "Healthy baby's online cabinet"

Ksenofontova Olga Leonidovna

Deputy chief physician of MBU "EKPC"

First of all, you need to understand the question - did the baby always prefer the same breast, or had there been no problems with alternating breasts before? If a child initially has a tendency to breastfeed with one breast, it is possible that he has problems with the cervical spine and neck muscles. On the other side and at the other breast, it is simply uncomfortable or painful for him to lie. This problem will be solved by a neurologist or pediatrician during examination, and this is usually detected almost once - in the first weeks of feeding. Then, for the duration of treatment, you should choose comfortable positions for feeding at both breasts - it can be from under the arm, hanging over the baby, in a cross cradle, and so on, the main thing is that the position of the child’s body is convenient for his muscles.

If the child does not have physical health problems, the reason for the refusal of one breast may be in the formation of the refusal as such. The baby may be sucking on a pacifier and developing nipple tangles, or selectively rejecting one breast in any position because it contains too much milk. And then, at the beginning of feeding, it pours too much from it, which makes the baby refuse it in favor of another breast - softer and with less pressure. Perhaps the reason for the refusal is the psychological discomfort of the baby - it is inconvenient for the mother to reproach the child with one of the breasts. She is not so comfortable putting the baby to her chest, and he catches this on a subconscious level, refusing the “unloved” breast. Sometimes the refusal of one breast is a kind of “demonstration of strength” by the baby and a way to control the mother, a kind of whim of the baby. Sometimes the breasts can be somewhat different from one another - it is easier and easier for the baby to get milk from one breast than from the other. And then the child can refuse a more “complex” breast in favor of a simpler one.

First of all, do not panic and be nervous. With a strong nervousness of the mother, the baby may refuse the breast completely, feeling her physical and emotional stress. At the same time, the mother’s milk in a state of stress is “clamped” by oxytocin in the chest and it becomes more difficult for the baby to get it. Pull yourself together and calm down. But you need to correct breast rejection at its earliest stages, until the baby has switched to breast rejection altogether or you yourself have come to terms with the fact that you will feed from one breast for the rest of the time. First of all, you need to understand for yourself that you are the mother of this baby and you are the leader in your couple, you are the main one and you will need to decide which breast and which of the feedings you will give to the baby. Feeding on demand implies not only the requirements of the baby itself, but also the requirement of the mother - if she has chest discomfort or a feeling of breast fullness, if she needs to feed in this situation with her left or right breast. It is extremely important to understand this for yourself and follow this rule. You need to be completely confident in yourself and in the correctness of all your actions. However, in such a delicate situation as the beginning or already completed refusal of the breast, you should not go too far either, insist on your opinion and breastfeeding with a certain breast should be extremely delicate, since violence in terms of breastfeeding can turn the situation in the opposite direction to you.

How to start the process of dealing with the rejection of one breast? First of all - change the program - that is, feed the baby with the unloved breast in an unusual position for him or use non-standard places for feeding him, sometimes you can feed the child with the unloved breast on a walk, in the kitchen with the noise of working appliances, in the car while traveling on business . Do the same when feeding for falling asleep: always start feeding by offering the baby his favorite breast, and when the baby starts to fall asleep, quickly change the breast to the one that he does not take well. Offer the same breast at night. When the baby wakes up for feeding, half-asleep children are usually more willing to agree to an unloved breast, if only to cling to their favorite milk faster again. Can be used to persuade you to take an unloved breast sources of white noise hair dryer, noise or splashing of water, sounds of nature or light music. Usually, breast rejection does not last long, and if you quickly eliminate the cause of discomfort and cope with your tension within yourself, then the child will quickly again be evenly applied to one and the other breast.

If you let the situation take its course, you can get a categorical rejection of the breast because there will actually be less milk in it due to its low stimulation. Then the baby will be capricious and offended by the lack of milk when trying to suck, and over time will refuse one breast altogether. Then you will have to feed with one breast, which entails a chain of new problems, for example, the formation of different breast sizes.

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Why a baby takes only one breast: a doctor's explanation


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Many breastfeeding mothers note that babies take one breast more often than the other. Usually this symptom is explained by the fact that one of the mammary glands produces more milk, it comes out easier, it is more convenient for the child to grab the nipple. However, it is not a matter of taste or improper attachment, because the child has no complaints about the other breast. But this may be one of the signs of a birth injury: a displacement of the bones of the base of the skull and a turn of the cervical vertebrae, manifested by torticollis.

The baby takes one breast because it is easier for him to turn to that side. For example, it is easier for a child to turn his head to the right side. Then, if you feed him in front of you, it is easier for him to take the left breast. And vice versa.

For a woman, feeding predominantly on one breast undoubtedly leads to uneven loading and the appearance or increase in breast asymmetry after the end of breastfeeding, which in itself is a serious reason to pay attention to this symptom.

Cranioposturologist, osteopath

Signs of torticollis

You can easily see them yourself:

  • the baby prefers to turn and tilt the head in one direction. Usually the head is tilted to one side and simultaneously deployed to the other. Especially clearly this symptom is noticeable in a dream, when the child involuntarily puts his head in the most convenient position for him.

  • the baby's neck is short, it seems that the head sits directly on the shoulders - the so-called puppet neck syndrome. It appears due to strong muscle tension. This is a kind of protective reaction to the existing birth trauma.

To check for torticollis, lay the child on their back with the head exactly in the center. If she turns a little or leans to the side, there should be no doubt - the child has mechanical disorders and they need to be treated, the sooner the better.

Why torticollis appears

Problem in the joint between the first cervical vertebra and the occipital bone. There, subluxation occurs - from slight to significant - and, as a result, the head assumes an incorrect position.

Most often, subluxation occurs due to birth trauma. The neck muscles of the child during childbirth were too stretched and twisted, the vertebrae were also displaced, the intervertebral ligaments were stretched. The neck reflexively tightens to limit the mobility of the cervical region, relieving it of pain when moving. When the child grows up, the neck becomes short and plump, muscle tension does not go anywhere.

Causes of torticollis

  • difficult, too fast or too long labor

  • administration of oxytocin or epidural anesthesia

  • if the child was squeezed out

  • torticollis often occurs during caesarean section.

However, it may be present even if everything went perfectly in your opinion. Mom and baby can have a completely different birth scenario. The most common discrepancy is that the mother says: “I gave birth quickly, easily, in 3 hours.” And for a baby, this means a rapid birth, one of the reasons for significant injuries.

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How to treat torticollis

Birth trauma and its consequences require treatment. Having cured torticollis, you will, of course, ensure that the child will still take both breasts well. But the main thing is to eliminate the risk of scoliosis in the future. If this symptom is left unattended, over time, all parts of the body will shift slightly. The incorrect position of the bones will determine the deterioration of blood flow in the brain. In a favorable case, the child can develop normally, but he will lack the intensity of arterial blood flow through the cerebral vessels in order to develop more actively and correctly.

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