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Dr Roger Henderson
Reviewed by Roger HendersonReviewed on 29.04.2024 | 3 minutes read

Possetting is when your baby brings back up undigested milk after each feed. It's really common in the first few months of life. This happens because your baby's digestive system is not very well developed after birth. The valve between the food pipe and the stomach normally works to prevent the backflow of milk. However, as this mechanism takes time to develop, your baby may spit up milk frequently in the meantime.

Coupling this with the fact that babies have little stomachs, and breastfeeding mothers tend to have an oversupply of milk at first, it’s easy to understand how possetting comes to occur. 

Causes of Possetting

Possetting in infants is often attributed to the immaturity of the digestive system, particularly the lower oesophageal sphincter, which is responsible for preventing the contents of the stomach from flowing back up into the oesophagus. In newborns and young infants, the lower oesophageal sphincter may be underdeveloped or less effective at closing fully, allowing milk or formula to reflux back into the oesophagus and occasionally be expelled through the mouth.

Other factors that may contribute to possetting in infants include:

Overfeeding. Feeding infants too quickly or offering large volumes of milk or formula at each feeding can overwhelm the stomach capacity, leading to possetting.

Air swallowing. Babies who swallow air during feeding, crying, or sucking on a pacifier may experience increased gas in the stomach, which can contribute to possetting.

Lying down after feeding. Placing infants in a lying-down position immediately after feeding can increase the likelihood of possetting, as gravity may facilitate the reflux of stomach contents into the oesophagus.

Food allergies or sensitivities. In some cases, possetting may be associated with food allergies or sensitivities, particularly to cow's milk protein or other components of infant formula.

Symptoms of Possetting

Possetting is characterised by the effortless expulsion of small amounts of milk or formula from the mouth, typically shortly after feeding. While possetting itself is usually benign and does not cause discomfort or distress to the infant, it may be accompanied by other symptoms, including:

  1. Frequent sicking up - Infants who posset frequently may exhibit a pattern of spitting up after most or all feedings.

  2. Arching of the back: Some infants may arch their backs or display signs of discomfort during or after feeding, which may be indicative of underlying gastro-oesophageal reflux (GOR) or gastro-oesophageal reflux disease (GORD).

  3. Irritability or fussiness: Infants experiencing frequent possetting may become irritable or fussy, particularly during or after feeding sessions.

  4. Poor Weight Gain: In rare cases, persistent possetting accompanied by inadequate weight gain or failure to thrive may indicate underlying gastrointestinal issues that require further evaluation and management.

Can I do anything to improve possetting?

If you notice your baby may be possetting more than usual, the first things to try are to:

  • Give them smaller but more frequent feeds - this will prevent them having too much and causing an over-spillage.

  • After feeding, it is important not to lay them down straight away as this puts pressure on the valve and encourages the backflow of food. Keep them upright for 15 to 30 minutes instead.

  • You may consider slightly raising the head of the cot when they are sleeping or the head of the mat when they are laying down to be changed. Just a book will do, under the mattress or mat.

  • Be careful when moving your baby around after feeds and when burping them to keep them upright.

If you notice they are still regurgitating quite a lot of milk and they are around the 5-month mark, provided they are showing good signs of being ready to wean, you can consider weaning them early. Solids don’t spill out as easily, and they’ll be growing out of possetting anyway.

2 common questions answered for possetting

Does possetting hurt?

Possetting is normal and does not cause your baby any harm or discomfort. It typically settles around 4 months old, as your baby's digestive system matures and they spend more time upright.

When should I worry about my baby?

  • If your baby is repeatedly sicking up more than they are keeping down, and they are losing weight or lethargic, then it is important to seek medical help straight away.
  • If you notice any blood, persistent cough, they are not feeding properly or are unsettled, then you should seek immediate medical help.
  • If you see repeated projectile vomiting, where a feed comes straight out at force and forms an arc, you should see urgent medical help.

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Dr Roger Henderson
Reviewed by Roger Henderson
Reviewed on 29.04.2024
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