Department of Pediatrics, University of Chicago and Northshore University HealthSystem, Evanston, Illinois, USA.
Pediatr Res. 2012 Aug;72(2):154-60. doi: 10.1038/pr.2012.65.
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.
Fetal H-I was achieved at three ages by sustained uterine ischemia in rabbits, mimicking the acute placental insufficiency of placental abruption.
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.
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.
胎儿缺氧缺血（H-I）会导致严重的发病率和死亡率。对于人类死产中死亡的时间知之甚少。胎儿的脆弱性随损伤时的年龄而变化，但尚不清楚胎儿损伤与胎儿死亡时间之间的关系。我们提出了这样一个问题，即胎儿死亡的时间是否受到损伤时的年龄影响。
通过持续的子宫缺血在兔子中模拟胎盘早剥的急性胎盘功能不全，在三个时期实现胎儿 H-I。
与 E25 和 E29 相比，妊娠 22 天（E22）的 H-I 导致围产期死亡较少。胎儿死亡分为早期和晚期围产期死亡。早期围产期死亡大多发生在 H-I 后立即，这些胎儿在足月前分娩。晚期围产期死亡发生在创伤和足月分娩之间。与 E22 缺氧缺血组相比，E25 缺氧缺血组的早期围产期死亡更为常见。
随着胎龄的增加，对缺氧的敏感性增加。围产期死亡可能在 H-I 后很长时间才发生。宫内缺氧缺血事件的时间不能从胎儿死亡的检测中推断出来。
