Risk factors in newborns with severe acidosis at birth

The identification of pre and postnatal risk factors as responsible of hypoxic-ischemic brain injury damage results very important in predicting the neurological outcome of newborns. The aim of this study was to investigate a possible correlation between pre and postnatal risk factors and severe acidosis at birth.

We collected all data of 559 newborns in our Hospital with risk factors. Risk factors have been subdivided in: maternal, placental, fetal, umbilical and obstetrical risk factors.

Of 559 newborns we collected umbilical cord pH and base excess (BE) in 411. Of these, 32 showed severe acidosis at birth: 29 full-term and 3 preterm. Fourteen out of 32 had almost one obstetric risk factor. Among all obstetric risk factors the application of the vacuum was statistically significant (9/59 applications of vacuum; P 0.003). No signs of brain injury were seen at cerebral echography in 29 cases of acidosis at birth. In all 3 premature neonates we found intraventricular hemorrhage, but without apparent neurological consequences at follow-up. Of 559 newborns with risk factors 21 have been intubated at birth. Only in premature deliveries a significant correlation between intubation at birth and acidosis was found.

The only factor which seems to play a significant role in developing a severe acidosis at birth is the use of vacuum in full-term deliveries. Umbilical cord pH and BE are related to intraventricular hemorrhage and need of intubation in delivery room for preterm infants. However, in both groups, no significant effect of acidemia on neurological outcome could be demonstrated.