Occurs in 1 to 4 per 1000 live births in the US and other Western populations, but is less common in Asia and Africa.[14]de Laffolie J, Turial S, Heckmann M, et al. Decline in infantile hypertrophic pyloric stenosis in Germany in 2000-2008. Pediatrics. 2012 Apr;129(4):e901-6.
http://www.ncbi.nlm.nih.gov/pubmed/22430445?tool=bestpractice.com
[15]To T, Wajja A, Wales PW, et al. Population demographic indicators associated with incidence of pyloric stenosis. Arch Pediatr Adolesc Med. 2005 Jun;159(6):520-5.
http://archpedi.ama-assn.org/cgi/content/full/159/6/520
http://www.ncbi.nlm.nih.gov/pubmed/15939849?tool=bestpractice.com
[16]Applegate MS, Druschel CM. The epidemiology of infantile hypertrophic pyloric stenosis in New York state, 1983 to 1990. Arch Pediatr Adolesc Med. 1995;149:1123-1129.
http://www.ncbi.nlm.nih.gov/pubmed/7550816?tool=bestpractice.com
[17]Schechter R, Torfs CP, Bateson TF. The epidemiology of infantile hypertrophic pyloric stenosis. Paediatr Perinat Epidemiol. 1997 Oct;11(4):407-27.
http://www.ncbi.nlm.nih.gov/pubmed/9373863?tool=bestpractice.com
[18]Sommerfield T, Chalmers J, Youngson G, et al. The changing epidemiology of infantile hypertrophic pyloric stenosis in Scotland. Arch Dis Child. 2008 Dec;93(12):1007-11.
http://www.ncbi.nlm.nih.gov/pubmed/18285388?tool=bestpractice.com
The prevalence is approximately four times greater in male infants than in female infants.[19]Rasmussen L, Green A, Hansen LP. The epidemiology of infantile hypertrophic pyloric stenosis in a Danish population, 1950-84. Int J Epidemiol. 1989 Jun;18(2):413-7.
http://www.ncbi.nlm.nih.gov/pubmed/2767855?tool=bestpractice.com
The disease is associated with a non-Mendelian familial pattern.[17]Schechter R, Torfs CP, Bateson TF. The epidemiology of infantile hypertrophic pyloric stenosis. Paediatr Perinat Epidemiol. 1997 Oct;11(4):407-27.
http://www.ncbi.nlm.nih.gov/pubmed/9373863?tool=bestpractice.com
A mother with pyloric stenosis is more likely than a father with pyloric stenosis to have a child with the condition; however, there are insufficient data to assess maternal impact.
The prevalence of pyloric stenosis appears to have decreased slightly over recent years, with evidence emerging that environmental exposure (e.g., maternal smoking), lower maternal education, and higher deprivation levels may increase incidence.[18]Sommerfield T, Chalmers J, Youngson G, et al. The changing epidemiology of infantile hypertrophic pyloric stenosis in Scotland. Arch Dis Child. 2008 Dec;93(12):1007-11.
http://www.ncbi.nlm.nih.gov/pubmed/18285388?tool=bestpractice.com
[20]Kapoor R, Kancherla V, Cao Y, et al. Prevalence and descriptive epidemiology of infantile hypertrophic pyloric stenosis in the United States: A multistate, population-based retrospective study, 1999-2010. Birth Defects Res. 2019 Feb 1;111(3):159-69.
http://www.ncbi.nlm.nih.gov/pubmed/30549250?tool=bestpractice.com
[21]Boybeyi-Turer O, Celik HT, Arslan UE, et al. Environmental exposure in the etiology of infantile hypertrophic pyloric stenosis: a systematic review and meta-analysis. Pediatr Surg Int. 2022 Jul;38(7):951-61.
http://www.ncbi.nlm.nih.gov/pubmed/35441884?tool=bestpractice.com
A first-born child is twice as likely to develop pyloric stenosis compared with a later-born child.[17]Schechter R, Torfs CP, Bateson TF. The epidemiology of infantile hypertrophic pyloric stenosis. Paediatr Perinat Epidemiol. 1997 Oct;11(4):407-27.
http://www.ncbi.nlm.nih.gov/pubmed/9373863?tool=bestpractice.com
[19]Rasmussen L, Green A, Hansen LP. The epidemiology of infantile hypertrophic pyloric stenosis in a Danish population, 1950-84. Int J Epidemiol. 1989 Jun;18(2):413-7.
http://www.ncbi.nlm.nih.gov/pubmed/2767855?tool=bestpractice.com
[22]Still G. Place in family as a factor in disease. Lancet. 1927;ii:795-853. Pyloric stenosis is more common in bottle-fed infants.[23]Habbick BF, Khanna C, To T. Infantile hypertrophic pyloric stenosis: a study of feeding practices and other possible causes. CMAJ. 1989 Feb 15;140(4):401-4.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1268663/pdf/cmaj00185-0055.pdf
http://www.ncbi.nlm.nih.gov/pubmed/2914261?tool=bestpractice.com
One retrospective cohort study of 1,074,236 babies born in the United States military health system found that there was a modestly increased risk of pyloric stenosis in premature infants compared with full-term infants (2.99 per 1000 premature infants vs. 2.25 per 1000 full-term infants; relative risk 1.33, 95% CI 1.16 to 1.54).[24]Stark CM, Rogers PL, Eberly MD, et al. Association of prematurity with the development of infantile hypertrophic pyloric stenosis. Pediatr Res. 2015 Aug;78(2):218-22.
http://www.ncbi.nlm.nih.gov/pubmed/25950452?tool=bestpractice.com