title: Birth outcomes of male and female patients with infantile hypertrophic pyloric stenosis--a population-based case-control study.
abstract: OBJECTIVE
  Most of the patients are affected by isolated infantile hypertrophic pyloric stenosis (IHPS) beyond the polygenic predisposition, the other factors in the multifactorial etiology are largely unknown. The main characteristic of IHPS is the robust male predominance, thus the aim of this study was to analyze birth outcomes in males and females whether they are different or not.
  
  
  METHODS
  The study samples included 241 cases with IHPS, 357 matched, and 38,151 population controls without any defect in the population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996.
  
  
  RESULTS
  The findings of this case-control study confirmed the well-known strong male excess (85.5%). The mean gestational age was somewhat longer and it is associated with a lower rate of preterm births. Mean birth weight did not show significant differences among the study groups, but the rate of low birthweight was higher in cases with IHPS. However, these differences were found only in males. Thus, intrauterine fetal growth restriction is characteristic only for male cases with IHPS.
  
  
  CONCLUSIONS
  Our study confirmed the well-known obvious male excess of cases with IHPS, but our findings suggest some differences in birth outcomes of male and female cases. Male cases with IHPS had intrauterine fetal growth restriction while females did not. These data may indicate some differences in the pathogenesis of IHPS in males and females.
authors.affiliation: a Department of Obstetrics and Gynecology , Military Hospital - State Health Centre , Budapest , Hungary .
authors.forename: Gabor
authors.initials: G
authors.lastname: Vermes
authors.affiliation: b 2nd Department of Obstetrics and Gynecology , Semmelweis University , Budapest , Hungary , and.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Mátrai
authors.affiliation: c Foundation for the Community Control of Hereditary Diseases , Budapest , Hungary.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Czeizel
authors.affiliation: b 2nd Department of Obstetrics and Gynecology , Semmelweis University , Budapest , Hungary , and.
authors.forename: Nándor
authors.initials: N
authors.lastname: Ács
mesh_terms: D001724:Birth Weight; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D046248:Pyloric Stenosis, Hypertrophic / Q000151:congenital*; D012727:Sex Characteristics
keywords: Birth order; birth outcomes; infantile hypertrophic pyloric stenosis; low birthweight; maternal age; population based case–control study; preterm birth