Pregnancy is a state associated with an enhanced metabolism and demand for O2 , which
may lead to the overproduction of reactive oxygen species (ROS) and hence to oxidative
stress. An elevated ROS level may result in delayed development and a low birth weight.
The aim of this study was to reveal the consequences of multiple pregnancies on the
redox status of neonatal human red blood cells (RBCs) and evaluate the role of endothelial
nitric oxide synthase (NOS3) - expressing RBCs in the generation of oxidative stress.
The study presents evidence of higher levels of production of hydrogen peroxide, peroxynitrite
and nitrate content in the RBCs of twin neonates, clearly reflected by an elevated
level of protein and lipid damages. This phenotype appears to be a consequence of
multiple pregnancies, regardless of the level of maturity or the birth weight of the
twins. Besides the higher level of ROS, there was a general decrease in the expression
of genes coding for antioxidants. The first data are presented on NOS3-expressing
neonatal human RBCs. The number of RBCs producing NOS3 was more than twice as high
in twin neonates compared to singletons, with no correlation to maturity.
