Background: There is limited evidence regarding the heart rate (HR) during the first minutes of life. Nonetheless, resuscitative actions within the first minute are partly guided by different HR levels. The advent of an electrocardiographic (ECG) HR sensor with early HR detection has provided the opportunity to study changes immediately following delivery. Objective: The objectives were to determine immediately following delivery: (i) the time to achievement of reliable ECG signals using dry electrodes, (ii) changes in HR, and (iii) the influence of the onset of breathing and cord clamping on the HR. Methods: Healthy term neonates were randomly included between July and October 2013. The HR was recorded by the ECG sensor, placed over the abdomen immediately after birth. Results: Fifty-five newborns were included. The median time from birth to placement of the HR sensor was 3 s (quartiles: 2 and 5), and the median time to the start of breathing was 6 s (quartiles: 2 and 15). The HR was around 120 beats/min (bpm) in the first seconds of life. As determined via breakpoint analysis, the HR increased by 1 beat in the first 40 s to 149 ± 33 bpm, followed by a moderate increase until 130 s and stabilization thereafter. After the onset of breathing, the HR decreased for 10 s and then increased. Minimal HR changes were observed after cord clamping. Conclusion: A dry-electrode ECG sensor detected reliable ECG signals almost immediately after birth. The normal HR increased significantly in spontaneously breathing infants during the first minute, influenced by the onset of breathing. Delayed cord clamping had a minimal impact on the HR, likely reflecting an earlier onset of breathing.

1.
Perlman JM, Wyllie J, Kattwinkel J, Wyckoff MH, Aziz K, Guinsburg R, Kim HS, Liley HG, Mildenhall L, Simon WM, Szyld E, Tamura M, Velaphi S; Neonatal Resuscitation Chapter Collaborators: Neonatal resuscitation: 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Part 7. Circulation 2015;132:S204-S241.
2.
Dawson JA, Kamlin CO, Vento M, Wong C, Cole TJ, Donath SM, Davis PG, Morley CJ: Defining the reference range for oxygen saturation for infants after birth. Pediatrics 2010;125:e1340-e1347.
3.
Kamlin CO, Dawson JA, O'Donnell CP, Morley CJ, Donath SM, Sekhon J, Davis PG: Accuracy of pulse oximetry measurement of heart rate of newborn infants in the delivery room. J Pediatr 2008;152:756-760.
4.
van Vonderen JJ, Hooper SB, Kroese JK, Roest AA, Narayen IC, van Zwet EW, te Pas AB: Pulse oximetry measures a lower heart rate at birth compared with electrocardiography. J Pediatr 10/2014;166-169.
5.
Kamlin CO, O'Donnell CP, Everest NJ, Davis PG, Morley CJ: Accuracy of clinical assessment of infant heart rate in the delivery room. Resuscitation 2006;71:319-321.
6.
Katheria A, Rich W, Finer N: Electrocardiogram provides a continuous heart rate faster than oximetry during neonatal resuscitation. Pediatrics 2012;130:e1177-e1181.
7.
Teitel DF, Iwamoto HS, Rudolph AM: Changes in the pulmonary circulation during birth-related events. Pediatr Res 1990;27:372-378.
8.
Bhatt S, Alison BJ, Wallace EM, Crossley KJ, Gill AW, Kluckow M, te Pas AB, Morley CJ, Polglase GR, Hooper SB: Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs. J Physiol 2013;591:2113-2126.
9.
Ersdal HL, Linde J, Mduma E, Auestad B, Perlman J: Neonatal outcome following cord clamping after onset of spontaneous respiration. Pediatrics 2014;134:265-272.
10.
Ersdal HL, Mduma E, Svensen E, Perlman JM: Early initiation of basic resuscitation interventions including face mask ventilation may reduce birth asphyxia related mortality in low-income countries: a prospective descriptive observational study. Resuscitation 2012;83:869-873.
11.
Köhler BU HC, Orglmeister R: QRS detection using zero crossing counts. Prog Biomed Res 2003;8:138-145.
12.
Muggeo VM: Estimating regression models with unknown break-points. Stat Med 2003;22:3055-3071.
13.
Farrar D, Airey R, Law GR, Tuffnell D, Cattle B, Duley L: Measuring placental transfusion for term births: weighing babies with cord intact. BJOG 2011;118:70-75.
14.
Karlberg P, Cherry RB, Escardo FE, Koch G: Pulmonary ventilation and mechanics of breathing in the first minutes of life, including the onset of respiration. Acta Paediatr 1962;51:121-136.
15.
Boere I, Roest AA, Wallace E, Ten Harkel AD, Haak MC, Morley CJ, Hooper SB, te Pas AB: Umbilical blood flow patterns directly after birth before delayed cord clamping. Arch Dis Child Fetal Neonatal Ed 2015;100:F121-F125.
16.
Hooper SB, Polglase GR, Roehr CC: Cardiopulmonary changes with aeration of the newborn lung. Paediatr Respir Rev 2015;16:147-150.
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