title: Magnesium sulphate and perinatal mortality and morbidity in very-low-birthweight infants born between 24 and 32 weeks of gestation in Japan.
abstract: OBJECTIVE
  Maternal exposure to magnesium sulphate has a neuroprotective effect in premature infants. This study aimed to examine this neuroprotective effect and the dose-response relationship in very-low-birthweight infants born between 24 and 32 weeks of gestation.
  
  
  METHODS
  A retrospective cohort study compared the rates of mortality and brain damage between three groups: no magnesium sulphate, low-dose (<50g) magnesium sulphate and high-dose (≥50g) magnesium sulphate.
  
  
  RESULTS
  Japanese maternal and neonatal databases were linked using six key parameters from 2003 to 2007. Of 298,514 deliveries, 9101 were very-low-birthweight infants. Among these, full matching was possible for 5562 infants. Of the fully-matched infants, 3763 were born between 24 and 32 weeks of gestation, and 1813 (48%) were followed-up beyond 18 months. A multivariate analysis of the data, including gestational age, sex, fetal growth restriction, antenatal steroids and low pH (<7.1), showed that the low-dose group had no beneficial effects in terms of a reduction in mortality or incidence of brain damage (cerebral palsy or mental retardation). The high-dose group showed a significantly higher mortality rate [odds ratio (OR) 1.9, 95% confidence interval (CI) 1.2-2.9]. A stratified subgroup analysis of infants born between 28 and 32 weeks of gestation showed that survivors in the low-dose group had significantly lower rates of cerebral palsy (OR 0.4, 95% CI 0.2-0.98) and brain damage (OR 0.2, 95% CI 0.1-0.9), while the high-dose group did not show any significant changes.
  
  
  CONCLUSIONS
  This study found that antepartum exposure to magnesium sulphate did not reduce the infant mortality rate or influence neurological outcomes. However, among infants born between 28 and 32 weeks of gestation, rates of cerebral palsy and brain damage were found to be significantly lower among survivors in the low-dose group.
authors.affiliation: Department of Obstetrics and Gynaecology and Centre for Perinatal Medicine, University of Miyazaki Faculty of Medicine, Miyazaki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohhashi
authors.affiliation: Department of Obstetrics and Gynaecology, Japanese Red Cross Fukuoka Hospital, Fukuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshitomi
authors.affiliation: Department of Obstetrics and Gynaecology and Centre for Perinatal Medicine, University of Miyazaki Faculty of Medicine, Miyazaki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sumiyoshi
authors.affiliation: Department of Obstetrics and Gynaecology and Centre for Perinatal Medicine, University of Miyazaki Faculty of Medicine, Miyazaki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawagoe
authors.affiliation: Maternal and Perinatal Care Unit, Oita Prefectural Hospital, Oita, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Satoh
authors.affiliation: Department of Obstetrics and Gynaecology and Centre for Perinatal Medicine, University of Miyazaki Faculty of Medicine, Miyazaki, Japan. Electronic address: hsameshima@med.miyazaki-u.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Sameshima
authors.affiliation: Department of Obstetrics and Gynaecology and Centre for Perinatal Medicine, University of Miyazaki Faculty of Medicine, Miyazaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ikenoue
mesh_terms: D001927:Brain Diseases / Q000517:prevention & control*; D002547:Cerebral Palsy / Q000517:prevention & control*; D016208:Databases, Factual; D036861:Delivery, Obstetric; D004305:Dose-Response Relationship, Drug; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007564:Japan; D008278:Magnesium Sulfate / Q000627:therapeutic use*; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D054238:Perinatal Mortality; D011247:Pregnancy; D012189:Retrospective Studies
chemical_list: D018696:Neuroprotective Agents; D008278:Magnesium Sulfate
keywords: Cerebral palsy; Low-birthweight infant; Magnesium sulphate; Mental retardation; Preterm delivery