title: Maternal and infant use of erythromycin and other macrolide antibiotics as risk factors for infantile hypertrophic pyloric stenosis.
abstract: OBJECTIVE
  To evaluate the risk for infantile hypertrophic pyloric stenosis (IHPS) among infants prescribed systemic erythromycin, infants prescribed a course of erythromycin ophthalmic ointment, and infants whose mothers were prescribed a macrolide antibiotic during pregnancy.
  
  
  METHODS
  Retrospective cohort study of infants born at an urban hospital from June 1993 through December 1999.
  
  
  RESULTS
  Of 14,876 eligible infants, 43 (0.29%) developed IHPS. Infants prescribed systemic erythromycin had increased risk of IHPS, with the highest risk in the first 2 weeks of age (relative risk = 10.51 for erythromycin in first 2 weeks, 95% CI 4.48, 24.66). Erythromycin ophthalmic ointment for conjunctivitis was not associated with increased risk of IHPS. Maternal macrolide antibiotics within 10 weeks of delivery may have been associated with higher risk of IHPS but the data were not conclusive.
  
  
  CONCLUSIONS
  This study confirms an association between systemic erythromycin in infants and subsequent IHPS, with the highest risk in the first 2 weeks of age. No association was found with erythromycin ophthalmic ointment. A possible association with maternal macrolide therapy in late pregnancy requires further study. Systemic erythromycin should be used with prudence in early infancy.
authors.affiliation: Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Mahon
authors.forename: M B
authors.initials: MB
authors.lastname: Rosenman
authors.forename: M B
authors.initials: MB
authors.lastname: Kleiman
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D004917:Erythromycin / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007231:Infant, Newborn; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011707:Pyloric Stenosis / Q000139:chemically induced* / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin