Infantile hypertrophic pyloric stenosis: a comparative study of incidence and other epidemiological characteristics in seven European regions.

OBJECTIVE: The objective of this study was to present epidemiologic data on infantile hypertrophic pyloric stenosis (IHPS) from seven well-defined European regions, and to compare incidence and changes in incidence over time between these regions.

METHODS: This was a population-based study using data from registries of congenital malformations (EUROCAT) for a period of more than two decades (1980-2002).

RESULTS: A total of 2534 infants were diagnosed with IHPS during the study period, giving an overall incidence of IHPS of 2.0 per 1000 live births (LB), ranging from 0.86 per 1000 LB to 3.96 per 1000 LB in the seven regions. A significant decrease in incidence was observed in two regions and a significant increase in incidence was observed in two other regions. Young maternal age (<20 years) significantly increased the risk of IHPS by 29% (adjusted by region; p < 0.01), and at maternal age of 30 years and older the risk decreased significantly (p < 0.01).

CONCLUSIONS: There were significant differences in the incidence of IHPS in the seven European populations. No uniform pattern of change in incidence was observed as the populations also differed in relation to trend over time with both significant increases and decreases over time. There is evidence that young maternal age is a risk factor for IHPS.