title: Risk factors of neonatal respiratory distress following vaginal delivery and caesarean section in the German population.
abstract: BACKGROUND
  The incidence of caesarean section (CS) is steadily rising world-wide. In particular, CS on maternal demand is performed more frequently. In parts, this might be due to insufficient information of pregnant women about neonatal risks of CS. We sought to specify neonatal outcomes following different modes of delivery, i.e. vaginal delivery, primary CS and secondary CS and to define risk factors for respiratory morbidity and hospitalization.
  
  
  METHODS
  We analysed 2073 births (gestational age > 35 weeks) during a two-year period at a tertiary obstetric and neonatal centre in Germany. Statistical analyses were performed for single parameters by SPSS as well as by logistic regression to account for possible confounders. Furthermore, extensive model calculation was done.
  
  
  RESULTS
  Respiratory morbidity was increased following primary and secondary CS (p = 0.001). By multiple logistic regression, the strongest effect on respiratory symptoms was seen with gestational age, each week more in utero reducing the risk by an odds ratio (OR) of 0.69 (95% CI: [0.61; 0.79]; p = 1.9 x 10(-8)). Furthermore, a significant interaction between mode of delivery and gestational age was found for the risk of respiratory symptoms (p = 0.0035).
  
  
  CONCLUSIONS
  For every eight newborns delivered by primary CS one more than expected with vaginal delivery is hospitalized. It is highly relevant to recognize that each week of gestational age reduces the risk of respiratory symptoms, especially if primary CS is performed. The higher rate of respiratory morbidity and neonatal admission following CS should be clearly recognized in counselling of pregnant women.
authors.affiliation: Centre for Pediatrics and Adolescent Medicine, University of Freiburg, Mathildenstrasse 1, Freiburg, Germany. andrea.heinzmann@uniklinik-freiburg.de
authors.forename: Andrea
authors.initials: A
authors.lastname: Heinzmann
authors.forename: Markus
authors.initials: M
authors.lastname: Brugger
authors.forename: Christina
authors.initials: C
authors.lastname: Engels
authors.forename: Heinrich
authors.initials: H
authors.lastname: Prömpeler
authors.forename: Andrea
authors.initials: A
authors.lastname: Superti-Furga
authors.forename: Konstantin
authors.initials: K
authors.lastname: Strauch
authors.forename: Marcus
authors.initials: M
authors.lastname: Krueger
mesh_terms: D002585:Cesarean Section / Q000009:adverse effects*; D016001:Confidence Intervals; D036861:Delivery, Obstetric / Q000009:adverse effects; D005260:Female; D005858:Germany / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011654:Pulmonary Edema / Q000453:epidemiology / Q000209:etiology*; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors