Delayed vs Immediate Cord Clamping Changes Oxygen Saturation and Heart Rate Patterns in the First Minutes after Birth

To build arterial oxygen saturation (SpO2) and heart rate (HR) percentiles for the first 10 minutes after birth in term infants born after an uneventful gestation, vaginal delivery, and delayed cord clamping (DCC) for ≥60 seconds, and to compare our results with previous ones constructed after immediate cord clamping. Preductal SpO2, HR, and timing of DCC immediately after complete fetal body expulsion were recorded. The pulse-oximeter was adjusted in the right wrist/hand and set at maximal intensity and measurements performed every 2 seconds. A total of 282 term newborn infants were included. The definitive data set comprised of 70 257 SpO2 and 79 746 HR measurements. Median and IQR of SpO2 (%) at 1, 5, and 10 minutes after birth were 77 (68-85), 94 (90-96), and 96 (93-98), respectively. HR (beats per minute) median and IQR at 1, 5, and 10 minutes after birth were 148 (84-170), 155 (143-167), and 151 (142-161), respectively. We found significantly higher SpO2 for the 10th, 50th, and 90th percentiles compared with the previous reference ranges for the first 5 minutes and HR for the first 1-2 minutes after birth. Spontaneously breathing term newborn infants born by vaginal delivery who underwent DCC ≥60 seconds achieved higher SpO2 and HR in the first 5 minutes after birth compared with term neonates born under the same conditions but with immediate cord clamping. Further studies in neonates undergoing cesarean delivery are under way.