[Factors related to severe neonatal acidosis in planned cesarean section. A case-control study].

Objectives: To identify factors related to the occurrence of severe neonatal acidosis in case of planned caesarean section.

Methods: Case-control study conducted between 1997 and 2016 among women with planned caesarean delivery at term. Cases were women whose neonates had neonatal arterial pH<7,0. For each case, two planned caesarean sections with neonatal pH≥7,0 were selected as controls. Women whose fetus had a congenital malformation and those whose anesthesia was not spinal anesthesia were excluded.

Results: Among the 5014 planned cesarean sections of the study period, 38 severe neonatal acidosis were observed (incidence of 0,76% CI95 [0,54-1,04]). Compared to 72 controls, the 36 caesareans with severe neonatal acidosis were associated with more frequent maternal obesity (BMI≥30kg/m), higher ephedrine doses, longer time from skin incision to infant delivery, and more extraction difficulties. After logistic regression, only maternal obesity remained associated with a significant increase in the risk of severe neonatal acidosis, ORa=3,73, 95%CI (1,11-12,56).

Conclusions: In case of planned cesarean section, the main risk factor for severe neonatal acidosis is the existence of maternal obesity.