Preterm neonatal cardiovascular instability: Does understanding the fetus help evaluate the newborn?

Summary 1. Preterm newborns, particularly very lo wb irth weight newborns, frequently experience intermittent hypotension and/or hypoperfusion. 2. Orga np erfusion is largely distinct from systemic hypotension, suggesting that changes in underlying v ascular tone are the major determinants of perfusion. 3. Preterm fetuses have a remarkable anaerobic tolerance and ability to survi ve m ajor insults with no or limited injury ,b alanced by relati ve i mmaturity of k ey autonomic responses. 4. Exposure to hypoxia-ischa emia and infection trigger comple xc hanges in vascular tone that evolv eo ver man yd ays, and there is e vidence that these are centrally controlled, and in part link ed with underlying organ metabolism.