Why is my baby vomiting after breastfeeding?

Updated July 19, 2017

When your baby spits up or vomits after breastfeeding it can be very concerning. Determining the cause is important for your baby's health and your peace of mind. Causes can vary from as simple as normal baby spit up to allergies to reflux, but your paediatrician should provide a diagnosis.

Spit Up or Vomit

Your baby's spit up can sometimes appear to be much more than it actually is. Take a teaspoon or tablespoon of water and spill it down your shirt, or on your couch, or wherever your baby's favourite target is, and see how much or how little it compares to the spit up. Vomiting usually distresses the baby, is in large quantities, and takes bodily effort. Spitting up typically doesn't seem to even phase the baby.

Can Be Normal

Spitting up can be a totally normal newborn phase. With an immature digestive system it is easy for the milk to flow back up. Sometimes, though, this is caused by the baby receiving too much milk too fast. In a breastfed baby this can be due to an oversupply or forceful let-down. Make sure baby has a good latch so that he is swallowing minimal air and nurse him on demand; small, frequent meals are easier on his small stomach.

Resolving Oversupply and Forceful Letdown

If baby is gaining well, producing enough dirty diapers for his age, and you suspect an oversupply is to blame, you can try block feeding. Use only one breast per meal, and if after a week or two you see no improvement, try using the same breast twice in a row before switching sides. Never restrict nursing. If your baby is overcome by your forceful let-down of milk--coughing, gulping, gasping, pulling off, or sometimes refusing to nurse--you can try different nursing positions. Recline so baby lies on top of you or try side-lying next to one another in bed. You can also nurse until let-down triggers, unlatch baby and wait for the fast flow to slow down, and then resume breastfeeding. Burp baby often, and if nothing else works, try block feeding as well.


Vomiting can sometimes be caused by gastro-oseophageal reflux disease (GERD). This only occurs in a small percentage of babies and can only be diagnosed by a doctor. Testing and treatment generally isn't needed for a baby that isn't in pain and is gaining weight well. Sometimes elevating your baby on a slight incline so that his head is higher than his stomach is enough to remedy the vomiting.


A small percentage of babies have sensitivities to foods in the mother's diet. You can diagnose these allergies with the help of a breastfeeding-savvy paediatrician. The most common allergens that cause problems when passed through the mother's breast milk are cow's milk, soy, wheat, corn, eggs and peanuts. Consider any family history of food allergies as well. Try elimination diets to determine what is affecting your baby. A complete two weeks of not consuming the potential allergen is necessary before determining its effect on the baby. Eliminate one food at a time until you notice change. A thorough journal is very helpful for noticing these changes.

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About the Author

Katherine Stevens has been writing since 2000, ranging from her first published piece about small birds in "Companion Parrot Magazine," to her more recent mothering articles in local parenting zines. Stevens has written various craft-related tutorials as well. She studied marketing communications at Columbia College.