<scp>CoolCuddle</scp> and Autonomic Regulation in Infants With Hypoxic‐Ischaemic Encephalopathy: An Intervention Study

AIM: We evaluated the impact of 'CoolCuddle', parental cuddling during therapeutic hypothermia intervention for hypoxic-ischaemic encephalopathy, on heart rate variability (HRV). METHODS: In this prospective, single-group, interventional study with repeated measures, we included infants ≥ 36 weeks' gestation undergoing hypothermia and CoolCuddle with HRV data. Time-domain HRV was assessed before, during, and after each cuddle. Primary outcomes were heart rate, mean RR interval (ANN), standard deviation of normal RR intervals, and root mean square of successive differences (RMSSD). RESULTS: In 65 CoolCuddles from 26 infants, CoolCuddle did not significantly alter HRV. However, infants with a 1-min Apgar < 7 had increased heart rates during (+2.33 bpm) and after (+3.27 bpm) cuddling, whereas those with higher Apgar scores showed decreases (-1.43 and -8.21 bpm) compared with pre-cuddle. Infants with Apgar < 7 or abnormal aEEG had reduced ANN during (-11.96 ms, -12.75 ms) and after (-19.89 ms, -19.00 ms), while those with higher Apgar or normal aEEG showed increases (+15.32 ms, +23.33 ms(during-cuddle); +63.94 ms, +55.06 ms (post-cuddle)). Maternal cuddling was associated with higher post-cuddle RMSSD (+1.06 ms) than paternal cuddling (-0.73 ms), (p = 0.04). CONCLUSION: While CoolCuddle had little overall effect on HRV, autonomic responses varied by asphyxia and encephalopathy severity and parent, suggesting differential modulation in vulnerable infants.