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

Abstract

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.