Fahri Fahri
Department of Pediatrics, Neonatal Intensive Care Unit, İstanbul Medeniyet University Medical Faculty, İstanbul, Türkiye.
Turk Arch Pediatr. 2025 May 2;60(3):251-257. doi: 10.5152/TurkArchPediatr.2025.24256.
The transition of the cardiovascular system from fetal life to extrauterine life occurs through different physiological mechanisms. The development of the lungs are parallel to the devel- opment of the cardiovascular system. Cardiac and vascular tone are affected by genetic and environmental factors, including hormonal influences and autonomic reflexes. During the tran- sition period, significant changes occur in preload, myocardial contractility, and afterload. The timing of cord clamping has a profound effect on these changes. Cerebral autoregulation is severely impaired in preterm infants, and cerebral blood flow is almost completely pressure- passive, especially in extremely preterm infants. Disrupted autoregulation is also more frequent in sick infants. Knowledge of transitional factors in different periods is essential for proper man- agement of newborn infants.
心血管系统从胎儿期到宫外生活的转变是通过不同的生理机制发生的。肺部的发育与心血管系统的发育并行。心脏和血管张力受遗传和环境因素影响，包括激素影响和自主反射。在过渡期，前负荷、心肌收缩力和后负荷会发生显著变化。脐带结扎的时机对这些变化有深远影响。早产儿的脑自动调节功能严重受损，脑血流几乎完全呈压力被动状态，尤其是极早产儿。患病婴儿中自动调节功能紊乱也更常见。了解不同时期的过渡因素对于新生儿的正确管理至关重要。
