title: Erythromycin use during pregnancy in relation to pyloric stenosis.
abstract: OBJECTIVE
  Newborn infants treated with erythromycin may be at risk for developing pyloric stenosis. Because erythromycin is known to cross the placenta and is a recommended treatment for chlamydia and other infections in pregnancy, we explored whether erythromycin taken during pregnancy might similarly lead to an increase in risk of pyloric stenosis.
  
  
  METHODS
  We used data collected between 1976 and 1998 as part of an ongoing case-control surveillance program. Cases were 1044 infants with a diagnosis of pyloric stenosis. Two control groups were used: 1704 nonmalformed infants and 15,356 infants with a wide range of other malformations. Odds ratios and 95% CIs were calculated by using data from each control group.
  
  
  RESULTS
  All odds ratio estimates are close to 1.0, all CIs include 1, and all upper 95% confidence bounds are less than 2.0.
  
  
  CONCLUSIONS
  We found no evidence of an increased risk of pyloric stenosis among infants born to mothers exposed to erythromycin during pregnancy.
authors.affiliation: Slone Epidemiology Unit, Boston University School of Medicine, Brookline, MA 02446, USA. clouik@slone.bu.edu
authors.forename: Carol
authors.initials: C
authors.lastname: Louik
authors.forename: Martha M
authors.initials: MM
authors.lastname: Werler
authors.forename: Allen A
authors.initials: AA
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D016022:Case-Control Studies; D004917:Erythromycin / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016017:Odds Ratio; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*; D011707:Pyloric Stenosis / Q000139:chemically induced*; D018570:Risk Assessment
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin