Observational study comparing heart rate in crying and non-crying but breathing infants at birth

Abstract

BackgroundStimulating infants to elicit a cry at birth is common but could result in unnecessary handling. We evaluated heart rate in infants who were crying versus non-crying but breathing immediately after birth.MethodsThis was single-centre observational study of singleton, vaginally born infants at ≥33 weeks of gestation. Infants who werecryingornon-crying but breathingwithin 30 s after birth were included. Background demographic data and delivery room events were recorded using tablet-based applications and synchronised with continuous heart rate data recorded by a dry-electrode electrocardiographic monitor. Heart rate centile curves for the first 3 min of life were generated with piecewise regression analysis. Odds of bradycardia and tachycardia were compared using multiple logistic regression.Results1155 crying and 54 non-crying but breathing neonates were included in the final analyses. There were no significant differences in the demographic and obstetric factors between the cohorts. Non-crying but breathing infants had higher rates of early cord clamping <60 s after birth (75.9% vs 46.5%) and admission to the neonatal intensive care unit (13.0% vs 4.3%). There were no significant differences in median heart rates between the cohorts. Non-crying but breathing infants had higher odds of bradycardia (heart rate <100 beats/min, adjusted OR 2.64, 95% CI 1.34 to 5.17) and tachycardia (heart rate ≥200 beats/min, adjusted OR 2.86, 95% CI 1.50 to 5.47).ConclusionInfants who are quietly breathing but do not cry after birth have an increased risk of both bradycardia and tachycardia, and admission to the neonatal intensive care unit.Trial registration numberISRCTN18148368.

Significance of Neonatal Heart Rate in the Delivery Room—A Review

“…Seven studies that described HR values in mainly non-ventilated newborn infants immediately after birth were included [ 5 , 8 , 9 , 10 , 11 , 12 , 13 ]. Characteristics of these studies are presented in Table 1 .…”

“…Kukka et al [ 13 ] used a dry-electrode ECG, a technology not contingent on skin cleaning and drying prior to application, and made HR percentile charts based on 1155 crying and 54 non-crying but breathing infants ≥ 33 weeks’ gestation ( Table 1 and Table 2 ). Similarly, Bjorland et al [ 11 ] used the same technology to describe HR in the first 5 min of life in 898 vaginally delivered term infants.…”

“…Bradycardia was diagnosed twice as often in the first two minutes of life via pulse oximetry vs. ECGs with a mean difference in HR between pulse oximetry and ECGs of −3 bpm in the first 10 min of life. Kukka et al [13] used a dry-electrode ECG, a technology not contingent on skin cleaning and drying prior to application, and made HR percentile charts based on 1155 crying and 54 non-crying but breathing infants ≥ 33 weeks' gestation (Tables 1 and 2). Similarly, Bjorland et al [11] used the same technology to describe HR in the first 5 min of life in 898 vaginally delivered term infants.…”