Aim of the Study
Infantile hypertrophic pyloric stenosis (IHPS) is a condition of unknown aetiology. Various risk factors have been postulated including both genetic and environmental risks. Previously published estimates of prevalence have calculated IHPS to affect approximately 1:300 children. We have noticed a reduction in the numbers of children being treated at our regional centre for IHPS and we sought to corroborate this with national trends.
A hospital coding database search identified all children who underwent a pyloromyotomy between 1st January 2008 and 31st December 2017. National Hospital Episode Statistics for England and Wales (HES data) was retrieved for the same time period to assess any national trend in incidence of pyloric stenosis. Simple linear regression analysis was used to assess for correlation between year of birth and incidence of IHPS.
Our regional data showed a significant reduction in the incidence of IHPS being treated at our centre during the study time period from 53 in 2008 to 23 in 2017. This mirrors national data showing a drop in incidence of IHPS from 1:581 births in 2008 to 1:915 births in 2016. Linear regression of the HES data to predict incidence of IHPS based on year of birth demonstrated a significant regression equation with an R2 value of 0.93. (Graph 1).
IHPS is becoming less common. This has both resource and training implications for paediatric surgical centres. The significant reduction in incidence over the last decade suggests an environmental risk factor has changed within the population. IHPS has been linked with maternal tobacco use. One potential explanation for our observations could be that maternal smoking at time of delivery has dropped from 15.1% in 2006 to 10.5% in 2016. Further work will be required to confirm or refute this hypothesis.