title: Intrauterine fetal demise can be remote from the inciting insult in an animal model of hypoxia-ischemia.
abstract: BACKGROUND
  Fetal hypoxia-ischemia (H-I) results in significant morbidity and mortality. Little is known about the timing of death in human stillbirths. The vulnerability of the fetus varies with age at the time of insult, but it is unknown what happens to the timing of fetal death in relation to a fetal insult. We asked the question of whether the timing of fetal death was influenced by the age at which the insult occurred.
  
  
  METHODS
  Fetal H-I was achieved at three ages by sustained uterine ischemia in rabbits, mimicking the acute placental insufficiency of placental abruption.
  
  
  RESULTS
  H-I at 22 d gestation (E22) resulted in fewer perinatal deaths than at E25 and E29. Fetal deaths were grouped into early and late perinatal deaths. Early perinatal death mostly occurred immediately after H-I and these fetuses delivered before term. Late perinatal death occurred between the insult and delivery at term gestation. Early perinatal death occurred more often in the E25 hypoxic-ischemic group as compared with those of the E22 hypoxic-ischemic group.
  
  
  CONCLUSIONS
  There is an increasing vulnerability to hypoxia with increasing gestational age. Perinatal deaths may occur long after the episode of H-I. The timing of an intrauterine hypoxic-ischemic event cannot be inferred from the detection of fetal death.
authors.affiliation: Department of Pediatrics, University of Chicago and Northshore University HealthSystem, Evanston, Illinois, USA. mderrick@northshore.org
authors.forename: Matthew
authors.initials: M
authors.lastname: Derrick
authors.forename: Ila
authors.initials: I
authors.lastname: Englof
authors.forename: Alexander
authors.initials: A
authors.lastname: Drobyshevsky
authors.forename: Kehuan
authors.initials: K
authors.lastname: Luo
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Sidhartha
authors.initials: S
authors.lastname: Tan
mesh_terms: D000022:Abortion, Spontaneous / Q000209:etiology*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000150:complications* / Q000401:mortality* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D010927:Placental Insufficiency / Q000209:etiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011817:Rabbits; D012044:Regression Analysis