Nitric oxide pathway adaptive changes: a new perspective of research from fetal growth, to delivery, to peri-natal effects.

S. PISANESCHI; A.M. SANCHEZ; S. BEGLIUOMINI; F.A.L. STRIGINI; P. GHIRRI; A. BOLDRINI; A.R. GENAZZANI; F. COCEANI; T. SIMONCINI

10-13 September, Rome, Italy

Congreso; 8th ESG Congress of the European Society of Gynecology.; 2009

European Society of Gynecology

There is evidence that infants delivered by elective caesarean section have a higher occurrence of respiratory problem compared to vaginally born babies. The complex mechanisms that control the labor remains unrevealed. Previous data regard the capacity of cerebrovascular regulation during asphyxia for prevention of brain oxygen deficit in newborns. We investigated the role of the NO system related to intrauterine growth, gestational age at birth and mode of delivery, by combining the analysis of NO, ADMA and S-NOHb in umbilical vessels. We analyzed newborns with different growth, born at term and preterm by elective caesarean section with/out prolonged labor, with/out intra-partum hypoxia. The preterm delivery is related with a decreased HUVEC NO release and an increased venous NO, associated with a lower concentration of S- NOHb. The umbilical vein NO and S-NOHb levels were significantly higher at birth in infants delivered vaginally or by caesarean section after labor versus babies born through elective caesarean section. Umbilical NO levels were significantly higher in groups with intra-partum hypoxia versus controls, independently of centiles of growth. We propose that S-NOHb may be consumed under fetal hypoxic conditions in preterm babies and [NO_] equivalents may be transferred to the umbilical vessel wall, as a compensatory response to preterm respiratory distress. We speculate that the oxidative stress experienced during parturition may have a role in preserving the babies from respiratory problems, through the NO pathway.