Maternal factors in the origin of infantile hypertrophic pyloric stenosis: A population‐based case‐control study

In most patients affected by isolated infantile hypertrophic pyloric stenosis ( IHPS ) the etiology is largely unknown. Thus, the aim of this study was to estimate possible maternal risk factors in the origin of IHPS . The study samples included 241 cases with IHPS , 357 matched controls and 38 151 population controls without any defect in the population‐based large dataset of the H ungarian C ase‐ C ontrol S urveillance of C ongenital A bnormalities, 1980–1996. Exposures that had been medically recorded in prenatal maternity logbooks during the critical period of IHPS were evaluated separately. The findings of this case‐control study suggested that – beyond the well‐known robust male excess (85.5%) – maternal hyperthyroidism ( OR with 95% CI : 4.17, 1.53–11.38) and oral nalidixic acid treatment ( OR with 95% CI : 6.53, 3.03–14.06) associated with a higher risk for IHPS in their children. In conclusion, our findings suggest that cases with IHPS had mothers with a higher proportion of hyperthyroidism and nalidixic acid treatment during pregnancy.