[Severe neonatal acidosis: comparison and analysis of obstetrical practices in two French perinatal centers]

To identify and compare risk factors for severe neonatal acidosis, defined by an umbilical artery pH inferior to 7.00, and clinical practices in two different perinatal centers.

In a retrospective study, from 2003 to 2008, in two university perinatal centers (Poitiers and Saint-Antoine in Paris) on all term pregnancies complicated by severe neonatal acidosis (umbilical artery pH<7.00), we elected to compare the following risk factors: maternal characteristics, medical and obstetrical histories, progress of pregnancy, labour and delivery as well as the neonatal status.

Among 23,508 births, 177 term newborns had severe neonatal acidosis. The rate was similar for both perinatal centers of Poitiers and Saint-Antoine (0.92% and 0.77% respectively). Factors associated with severe neonatal acidosis were similar in both centers: maternal age, thick meconium, prior cesarean section. There were differences in obstetrical practices between the two centers: there were more caesarean sections and assisted vaginal deliveries in Paris and more inductions of labour in Poitiers.

Severe neonatal acidosis is associated with the geographical origin, the progress of labour and the mode of delivery. It seems that severe neonatal acidosis is unrelated to cesarean delivery.