Factors associated with the use of supplemental oxygen or positive pressure ventilation in the delivery room, in infants born with a gestational age ≥ 34 weeks

Background: Approximately 5-10 % of newborns require some form of resuscitationupon delivery; several factors, such as maternal abnormal conditions, gestational age and type of delivery could be responsible for this trend. This study aimed to describe the factors associated with the need for positive pressure ventilation (PPV) via a mask or endotracheal tube and the use of supplemental O2 in newborns with a gestational age greater than 34 weeks in Brazil. Methods: We performed a cross-sectional study and obtained data from the Birth in Brazil Survey. The inclusion criterion was a gestational age >= 34 weeks. Exclusion criteria were newborns with congenital malformations, and cases with undetermined gestational age or type of delivery (vaginal, pre labor cesarean section and cesarean section during labor). The primary outcomes were need of PPV via a mask or endotracheal tube and the use of supplemental oxygen without PPV. Confounding variables, including maternal age, source of birth payment, years of maternal schooling, previous birth, newborn presentation, multiple pregnancy, and maternal obstetric risk, were analyzed. Results: We included 22,720 newborns. Of these, 2974 (13.1 %) required supplementary oxygen. PPV with a bag and mask was used for 727 (3.2 %) newborns and tracheal intubation for 192 (0.8 %) newborns. Chest compression was necessary for 136 (0.6 %) newborns and drugs administered in 114 (0.5 %). 51.3 % of newborns were delivered by cesarean section, with the majority of cesarean sections (88.7 %) being performed prior to labor. Gestational age (late preterm infants: (Relative Risk-(RR) 2.46; 95 % (Confidence interval-CI 1.79-3.39), maternal obstetric risk (RR 1.59; 95 % CI1.30-1.94), and maternal age of 12-19 years old (RR 1.36; 95 % CI1.06-1.74) contributed to rates of PPV in the logistic regression analysis. Newborns aged between 37-38 weeks of gestaional age weren't less likely to require PPV compared with those aged 39-41 weeks of gestational age. Conclusions: Late preterm infants, previous maternal obstetric risks and maternal age contributed to the higher needs of PPV and use of O2 in the delivery room. These variables need to be considered in planning care in the delivery room.