title: Changing obstetric practices associated with decreasing incidence of meconium aspiration syndrome.
abstract: OBJECTIVE
  To describe changes in neonatal and obstetric practices that may have contributed to the decreasing incidence of meconium aspiration syndrome in our population during this time.
  
  
  METHODS
  We compared neonatal and obstetric characteristics of 61 infants diagnosed with meconium aspiration syndrome with 1365 infants born through moderate or thick meconium-stained amniotic fluid at more than 37 weeks' completed gestation. Data were prospectively collected, and all respiratory diagnoses were concurrently made. Three distinct birth year groups were analyzed based on changing obstetric practice paradigms.
  
  
  RESULTS
  Meconium aspiration syndrome decreased nearly four-fold from 1990-1992 to 1997-1998 (5.8% to 1.5% of meconium-stained infants more than 37 weeks; P <.003). The only change in neonatal characteristics was a 33% decrease in births more than 41 weeks with a reciprocal 33% increase in births 38-39 weeks during 1997-1998. Significant changes in obstetric practice included more frequent diagnosis of nonreassuring fetal heart rate patterns, greater use of amnioinfusion, and increased cesarean delivery rate in 1997-1998. By logistic regression analysis, the only consistent risk factor for meconium aspiration syndrome across all three epochs was the presence of tracheal meconium.
  
  
  CONCLUSIONS
  Reduction in post-term delivery was the most important factor in reducing meconium aspiration syndrome.
authors.affiliation: Department of Pediatrics, Wilford Hall Medical Center, Lackland AFB, Texas, USA.
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Yoder
authors.forename: Erica A
authors.initials: EA
authors.lastname: Kirsch
authors.forename: William H
authors.initials: WH
authors.lastname: Barth
authors.forename: Michael C
authors.initials: MC
authors.lastname: Gordon
mesh_terms: D002585:Cesarean Section / Q000706:statistics & numerical data; D002821:Chorioamnionitis / Q000175:diagnosis / Q000628:therapy; D005260:Female; D005323:Fetal Monitoring; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008471:Meconium Aspiration Syndrome / Q000453:epidemiology* / Q000517:prevention & control; D009774:Obstetrics; D010818:Practice Patterns, Physicians'; D011247:Pregnancy; D011256:Pregnancy Outcome; D011273:Pregnancy, Prolonged / Q000502:physiology; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal / Q000706:statistics & numerical data