New research says that bottle feeding appears to increase the risk of babies developing hypertrophic pyloric stenosis, a form of stomach obstruction characterized by severe and frequent projectile vomiting and most common among infants in their first 2 months of life.
Surgery, called pyloromyotomy, may be needed to clear the hypertrophic pyloric stenosis (HPS), which occurs when the smooth muscle layer of the pylorus (the “gateway” between the stomach and small intestines) thickens.
Dr. Jarod P. McAteer from Seattle Children’s Hospital and colleagues say in the study that although this is a fairly common condition – it occurs in approximately 2 in 1,000 births – the cause remains unknown.
This study, published in JAMA Pediatrics, sets out to establish if bottle feeding during early infancy increases the risk of developing HPS, and if so, how the risk is modified by other factors.
Bottle feeding ‘may play a role in HPS’
The researchers found that the incidence of HPS decreased from 14 per 10,000 births in 2003 to 9 per 10,000 births in 2009. They note that the popularity of breastfeeding also increased during that time from 80% in 2003 to 94% in 2009.
The study revealed that bottle-fed infants were more likely to develop HPS, compared with controls (19.5% vs. 9.1%). The odds of an infant developing HPS also increased if they were male, and when mothers were 35 years and older and multiparous (having given birth more than once before.).
In an accompanying editorial, Dr. Douglas C. Barnhart from the Primary Children’s Hospital, Salt Lake City, writes:
“While the data seem convincing that bottle feeding increases the risk, the reason is not clear.”
“Further understanding of the pathogenesis of hypertrophic pyloric stenosis will come from both basic research and more detailed epidemiologic studies,” Barnhart concludes.
Dr. McAteer and his colleagues agree, adding:
“Further studies are warranted to validate these findings and to look more closely at the speculative mechanisms, including possible hormonal effects, underlying the bottle feeding-HPS association.”