Table 1. Fetal and maternal mean RR interval duration, standard deviation (SDNN) and root mean square of successive differences (RMSSD) found in the subjects’ 18 min. data sets as well as in their synchronization epochs (SE).

			fetal			maternal
		Control	Exercise		Control	Exercise
		n = 19	n = 21	p-value	n = 19	n = 21	p-value
RR interval (ms)
18 min.	original	427±33	445±30	0.074	674±62	718±116	0.226
18 min.	surrogate	n.a.	n.a.		676±63	719±115	0.258
SE	original	420±35	430±34	0.294	646±59	691±122	0.294
SE	surrogate	430±33	442±28	0.294	672±65	715±118	0.187
SDNN (ms)
18 min.	original	21.4±6.2	29.3±9.6	0.012	44.9±12.5	57.6±22.2	0.138
18 min.	surrogate	n.a.	n.a.		44.4±12.8	56.6±22.0	0.124
SE	original	5.3±1.5	6.2±1.5	0.054	13.5±4.1	19.1±12.9	0.093
SE	surrogate	6.6±1.6	8.1±2.2	0.044	17.0±4.9	24.2±14.0	0.057
RMSSD (ms)
18 min.	original	6.2±2.1	8.6±3.8	0.015	20.8±9.1	35.2±26.9	0.074
18 min.	surrogate	n.a.	n.a.		21.1±9.1	35.8±27.9	0.074
SE	original	4.1±1.1	4.5±1.3	0.258	12.3±6.0	20.3±19.7	0.083
SE	surrogate	4.8±1.5	5.7±1.6	0.054	16.2±7.8	25.3±21.1	0.099

All values are given for the original data as well as the surrogate data, except for the 18 min. fetal data sets (only the maternal data sets were shuffled, see text). The values are compared between the Control and Exercise groups. p-values <0.05 in bold type.

n.a., not applicable.