Minakami H, Kimura H, Honma Y, Tamada T, Sato I
Department of Obstetrics and Gynecology, Jichi Medical School, Tochigi, Japan.
Gynecol Obstet Invest. 1995;40(3):174-8. doi: 10.1159/000292330.
To determine when the extrauterine environment becomes safer than the intrauterine environment with respect to fetal (neonatal) life, we analyzed all 4,896,505 livebirths, all 21,222 stillbirths, and all 7,513 early neonatal deaths after 26 weeks gestation that were recorded between 1989 and 1992 in Japan. Although the risk of early neonatal death ( < 1 week of age) and of neonatal death ( < 4 weeks of age) greatly exceed the risk of stillbirth at 26 weeks of gestation, those risks declined sharply by 39 weeks of gestation, then increased, while the risk of stillbirth within 1 and 4 weeks exceeded the risks of early neonatal death and of neonatal death at and beyond gestational weeks 40 and 38, respectively, for a singleton pregnancy. A similar reversal occurred at 37 and 35 weeks of gestation for multiple pregnancy. Neonates born at 39 and 37 weeks of gestation for singleton and multiple pregnancies, respectively, had the best outcome. It is concluded that the chance of survival for fetuses reaching 40 and 37 weeks of gestation for singleton and multiple pregnancies, respectively, were higher in the extrauterine than the intrauterine environment in Japan today.
为了确定就胎儿（新生儿）生命而言，宫外环境何时比宫内环境更安全，我们分析了1989年至1992年期间日本记录的所有4896505例活产、所有21222例死产以及所有26周妊娠后发生的7513例早期新生儿死亡病例。尽管早期新生儿死亡（<1周龄）和新生儿死亡（<4周龄）的风险在妊娠26周时大大超过死产风险，但这些风险在妊娠39周时急剧下降，然后上升，而单胎妊娠在1周和4周内的死产风险分别超过妊娠40周及以后和38周及以后的早期新生儿死亡和新生儿死亡风险。多胎妊娠在妊娠37周和35周时也出现了类似的逆转。单胎和多胎妊娠分别在妊娠39周和37周出生的新生儿结局最佳。得出的结论是，在当今日本，单胎和多胎妊娠分别达到妊娠40周和37周的胎儿在宫外环境中的生存机会高于宫内环境。
