Whether they are breastfeeding or not, most women have slight variations in breast size, just as most of us have slight variations in shoe size, for instance, and when it comes to producing milk, it’s common to have one breast that is a better milk maker than the other.
It’s no fun though, when one breast becomes much bigger than the other and your baby favours the ‘good’ side, perpetuating the extreme lopsided look.
Why does one boob make more milk?
The basic rule of milk production is that the more milk is removed, the more milk your breasts will produce, so uneven breast size can be influenced by your baby feeding more from one side than the other. A preference for one side can be either baby driven or mother directed. You may find it more comfortable to feed on one side so feed your baby more often on that side or your baby may have a preference so feeds more from one side. And when baby feeds more from one side, this breast will make more milk – and become bigger!
Reasons your baby prefers one side include:
Faster milk flow - one breast may have more working milk ducts and alveoli so produces a greater volume of milk or if you have had breast surgery on one side this also can affect supply in that breast . One breast can have a faster milk flow or more forceful milk ejection reflex and whether your baby prefers a faster flow or is overwhelmed by this, could determine which side is easier to feed from.
If a slow let down seems to be an issue, you can start your baby on the preferred side then when you get a letdown and your milk flows faster, switch sides. You can also try breast compressions to encourage a faster flow to to keep your baby feeding on that side.
Nipple shape - Just as most women have breasts that are asymmetrical, you are also likely to have slightly (or more pronounced) variations between nipple shape and size, making one side easier for your baby to latch. This too can influence breast preference and feeding behavior.
Milk taste – if you have mastitis, your milk may taste salty on the affected side so this can lead your baby to feed more from the unaffected side – you actually need to empty the ‘sick’ breast to help you recover from mastitis.
Pain – your newborn may have a birth injury such as sore shoulder that makes feeding on one side uncomfortable. Check with your doctor. If your baby prefers lying on one side, always turns his head to one side and prefers one breast, often seeing an osteopath, a pediatric chiropractor or physiotherapist can make a difference.
If breast preference happens suddenly, consider could your baby have a sore ear or does he have a sore arm or leg after immunization that is causing pain on one side?
Balancing your boobs
If uneven breasts don’t bother you, you don't need to do anything, except perhaps add an extra breast pad or two to your bra if you are feeling self conscious or your bras don't fit. Or you could take a look at the gorgeous Arden Bra which has independently adjustable cups so will accommodate differing sized breasts. However, if you are concerned, uncomfortable or anxious that one side might stop producing milk altogether, you can try and even things up by stimulating milk production in the low producing side.
Start feeding on the ‘bad’ side first- your baby will usually feed more voraciously at first so by draining the first side you will help increase supply in that side. You can then feed off the fuller side until that is comfortable then switch back to the smaller side to finish because once your baby is feeling satisfied he is more likely to suck for comfort on the less full side and this extra stimulation may help to boost milk supply in your smaller breast.
Express yourself – if baby is reluctant to feed from your smaller side , it can be helpful to pump for 5 - 10 minutes (the small side only) after feeds for some extra stimulation. Or if you have time, you could try pumping from the smaller side between a few feeds.
Position your baby – although it’s important to try and sort out reasons for your baby’s breast preferences such as discomfort, you can encourage feeding from the smaller side by holding your baby the same way on both sides. For example, if you feed your baby on the ‘good side’ in a cradle hold, you can gently slide him across and try a football hold when you switch sides.
Get moving -You can also encourage longer sucking on the smaller side by rocking, standing or walking around as you feed from the smaller side.
Try a sleepy feed - try to feed from the least preferred side when your baby is drowsy or just stirring in his sleep when he will instinctively suck.
Have a breast check – if your baby refuses one breast and this is ongoing, please see your doctor and get a breast check to make sure there isn’t anything unusual happening in that breast.
Whatever the reasons for lop sided breasts or your baby’s preference for one breast over the other, the good news is that this doesn’t affect overall milk production. Mothers can successfully breastfeed with just one milk-producing breast. And, after weaning, your breasts will even out again – you won't be left with one giant breast and one smaller one forever if they were pretty even in the first place.