Table 8.

Mean and standard deviations for total heart rate variability in response to acute pain at less than 7 postnatal days.

Gestational age	Reference	Mean total HRV	SD
32–34 weeks	Stevens and Johnston [64]	4.52	2.95
37–42 weeks	Lindh et al. [55]	4.30	0.40
	Lindh et al. [54]	4.10	0.35

Note. HRV = heart rate variability, SD = standard deviation.