Table 2.

Literature overview of FHRV power values.

Reference	First author	Year	VLF	LF	MF	HF	Measure unit	Foetal state
[38]	Cerutti	1989	27.30		9.30	44.20	%	Breathing
			69.20		25.30	2.60	%	Nonbreathing
			8.10		2.80	10.20	ms2	Breathing
			75.40	27.60	2.90		ms2	Nonbreathing
[50]	Groome	1994	35.6 ± 15.3	28.6 ± 10.7		35.8 ± 13.2	%	Breathing
			30.9 ± 11.6	28.6 ± 9.5		40.5 ± 13.9	%	Nonbreathing
			0.9 ± 0.67	0.62 ± 0.37		0.77 ± 0.29	ms2	Breathing
			0.4 ± 0.43	0.33 ± 0.24		0.42 ± 0.21	ms2	Nonbreathing
[43]	Signorini	2003		324 ± 174	28 ± 26		ms2	Active
				123 ± 95	16 ± 9		ms2	Quiet
			31.10	56.84	8.37	0.18	%	Active
			33.9 ± 15.7	48.3 ± 18.1	12.4 ± 5.6	1.27 ± 1.31	%	Quiet
[59]	Yum	2004		100.5 ± 6.3		15.5 ± 0.9	ms2
[63]	van Laar	2009		0.8 ± 0.08		0.07 ± 0.03	%	Active
				0.69 ± 0.1		0.14 ± 0.06	%	Quiet
				429 ± 410		21.3 ± 7.3	ms2	Active
				92 ± 79.9		10.5 ± 5.3	ms2	Quiet
[70]	Ferrario	2009	274.82 ± 234.41	136.76 ± 84.21	19.13 ± 10.93	4.8 ± 3.61	ms2
				83.82 ± 4.79	12.26 ± 2.51	3.93 ± 2.55	%
[69]	Van Leeuwen	2014		45 ± 43		24 ± 12	ms2

Results from the studied literature works (listed in chronological order) on FHRV power estimation.