. Author manuscript; available in PMC: 2013 Oct 1.

Published in final edited form as: Physiol Meas. 2012 Sep 4;33(10):1563–1583. doi: 10.1088/0967-3334/33/10/1563

Table 3.

Pearson correlation between the variability measures and gestational age (GA) for the three HR sub-series and as a function of the defined groups (Groups I, II and III). The number of total HR sub-series analyzed for each group is given in parentheses. As for table 2, the number of 3 and 2 min HR sub-series included in Groups I, II and III differ because the groups were defined separately for these HR sub-series. Only significant correlations are reported.

5 min HR sub-series
	Group I (19)	Group II (20)	Group III (7)
SDNN	−0.49^*	−0.45^*
RMSSD		−0.51^*
SDNN/RMSSD	−0.61^**
LTI	−0.59^**
SampEn		0.44^*

3 min HR sub-series
	Group I (41)	Group II (42)	Group III (9)
STV	0.33^*
SDNN/RMSSD	−0.33^*

2 min HR sub-series
	Group I (49)	Group II (34)	Group III (9)
SDNN	−0.43^**		−0.74^*
RMSSD		−0.36^*
SDNN/RMSSD	−0.29^*
LTI	−0.47^***
ApEn	0.36^**
SampEn	0.38^**

^***

p < 0.001,

^**

p < 0.01,

p < 0.05.