title: Is the neonatal creatine phosphokinase level a reliable marker for fetal hypoxia?
abstract: OBJECTIVE
  The creatine phosphokinase (CPK) level is believed to increase in neonatal peripheral blood after tissue damage, including damage from perinatal hypoxia. However, it is not clear whether it is truly a reliable marker for fetal hypoxia. We investigated the chronological changes in neonatal CPK and the reliability of CPK as a marker for fetal hypoxia.
  
  
  METHODS
  Sixty term neonates admitted to the neonatal intensive care unit at Tokyo Women's Medical University Medical Center East from April 2009 to April 2010 were enrolled in this study. We evaluated whether asphyxia and fetal heart rate (FHR) abnormality could predict the neonatal CPK level by using receiver-operator curve analysis. We also compared umbilical cord blood pH levels with neonatal CPK levels. In addition, we investigated factors that influence neonatal CPK in non-asphyxia cases.
  
  
  RESULTS
  The median value of CPK peaked on day 1. There were no significant differences in CPK levels regardless of the presence of asphyxia or FHR abnormality. Non-asphyxiated neonates with older gestational ages and amniotic fluid abnormalities had significantly higher levels of CPK.
  
  
  CONCLUSIONS
  Our results indicate that the neonatal CPK level is not an appropriate marker for retrospectively predicting either asphyxia or FHR abnormality. There are influencing factors other than asphyxia that increase neonatal CPK. Therefore, one should be careful when making a diagnosis of perinatal hypoxia based solely on increased levels of neonatal CPK after birth.
authors.affiliation: Department of Obstetrics and Gynecology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Muraoka
authors.affiliation: Department of Obstetrics and Gynecology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Takagi
authors.affiliation: Department of Obstetrics and Gynecology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Morita
authors.affiliation: Department of Obstetrics and Gynecology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagano
authors.affiliation: Department of Neonatology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Henmi
authors.affiliation: Department of Neonatology, Tokyo Women's Medical University, Medical Center East, Tokyo, Japan.
authors.forename: Hisaya
authors.initials: H
authors.lastname: Hasegawa
mesh_terms: D000328:Adult; D001238:Asphyxia Neonatorum / Q000097:blood / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D005311:Fetal Hypoxia / Q000097:blood* / Q000175:diagnosis*; D005865:Gestational Age; D006340:Heart Rate, Fetal; D006801:Humans; D007231:Infant, Newborn; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase
keywords: fetal acid base status; intrapartum fetal assessment; perinatal brain damage