title: Impact of pre-eclampsia in extremely premature infants: Population-based study.
abstract: BACKGROUND
  The relationship between chorioamnionitis (CAM) and neonatal mortality has been extensively investigated, but that of maternal pre-eclampsia and neonatal mortality is unclear. We investigated neonatal mortality and morbidity of maternal pre-eclampsia and clinical CAM in extremely premature infants using data from a population-based cohort study.
  
  
  METHODS
  We retrospectively analyzed data obtained from the Neonatal Research Network in Japan, a population-based cohort study (n = 18 900) conducted to clarify the clinical characteristics and morbidity of very low-birthweight infants. Patients were divided into four diagnosis-based groups for comparative analysis: sole pre-eclampsia; sole clinical CAM; concurrent pre-eclampsia and clinical CAM; and non-diagnosis (of pre-eclampsia and clinical CAM).
  
  
  RESULTS
  Mortality was higher in the pre-eclampsia groups compared with the groups without (18.3%, 84/459 vs 14.0%, 567/4059; OR, 1.38; 95%CI: 1.07-1.78). In contrast, mortality was not affected by presence of clinical CAM (with, 13.7% 182/1328 vs without, 15.0% 469/3190; OR, 0.92; 95%CI: 0.77-1.11). With regard to small for gestational age, the mortality rate increased by two-three-fold as gestational week decreased. The complication survival rate in the whole group was 35% (1135/3218).
  
  
  CONCLUSIONS
  Maternal pre-eclampsia is associated with poor prognosis in extremely premature infants. We also need to deliberate on the trade-off between the advantages of early rescue from pre-eclampsia and risk of prematurity.
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan.|Department of Consultation, Kurashiki Clinical Research Institute, Okayama, Japan.|Department of Pediatrics, Kurashiki Central Hospital, Okayama, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Tokumasu
authors.affiliation: Department of Pediatrics, Kurashiki Central Hospital, Okayama, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Tokumasu
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawakami
mesh_terms: D002821:Chorioamnionitis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007226:Infant Mortality / Q000639:trends; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007564:Japan / Q000453:epidemiology; D009017:Morbidity / Q000639:trends; D011159:Population Surveillance; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D012189:Retrospective Studies
keywords: chorioamnionitis; infant; mortality; pre-eclampsia; preterm