Bottle-feeding may raise risk of stomach blockage in babies
Newborn babies who are bottle-fed have a higher risk of a stomach blockage called hypertrophic pyloric stenosis, a study suggests. But their overall risk remains fairly low.
BMJ Group News
What do we know already?
Hypertrophic pyloric stenosis (HPS) happens when the lower part of a baby’s stomach (called the pyloris) becomes narrowed. This stops the contents of the stomach from passing into the small bowel. As a result, the baby vomits frequently and forcefully.
Around 2 in every 1,000 babies develop HPS, usually in the first two months of life. An operation to widen the pyloris can cure the condition. This is one of the most common surgeries for babies.
Although doctors know how to treat HPS, they don’t know why it develops. Studies show that certain things can increase a baby’s risk, including being a boy, having a mother who is young or who smokes, and being a first-born child. Some research also suggests that being bottle-fed may increase the risk. However, the studies looking at this have been fairly small.
In the new study, researchers reviewed health information on all babies born in Washington state in the US, from 2003 to 2009. They found more than 700 babies who’d had surgery for HPS, and matched each of these with 10 babies born in the same year who didn’t have the condition. They then compared these groups to see if bottle-feeding was more common among those who developed HPS. Babies were considered to be bottle-fed if they had any bottle-feeding while in hospital after being born.
What does the new study say?
Nearly 20 in every 100 babies with HPS were bottle-fed, compared with only around 9 in every 100 babies who didn’t develop the condition. After taking into account other things that can affect a baby’s risk of HPS, the researchers estimated that bottle-fed babies were more than twice as likely to develop the condition.
This may sound like a large increase in risk, but bear in mind that the actual increase was fairly small. For example, if a breast-fed baby had a 2 in 1,000 risk of HPS, the risk for a bottle-fed baby would be between 4 in 1,000 and 5 in 1,000.
How reliable is the research?
This was a large, well-conducted study that gathered information from reliable health databases. This makes it more likely that the link between bottle-feeding and HPS is genuine.
However, this type of study can’t show cause and effect, so we can’t be certain that bottle-feeding was what raised the babies’ chance of HPS. It’s possible that something else increased their risk, which the researchers weren’t able to take into account.
It’s also not clear from these findings which aspects of bottle-feeding might be linked to HPS. It could be that formula milk plays a role, but some babies in the study may have had breast milk in their bottle. It’s also possible that something about the bottles, such as their plastics, could have an effect.
What does this mean for me?
If you are pregnant or have a newborn baby, these findings suggest that bottle-feeding may increase your baby’s risk of HPS, although the reasons why aren’t yet clear.
While more research will need to explore this, we do know that breast-feeding offers babies many benefits, including providing all the nutrients they need, along with antibodies to protect against disease. A lower risk of HPS may be another benefit to consider.