Development of daily rhythmicity in heart rate and locomotor activity in the human fetus

Table 2 ECG and locomotor activity of the fetus in "quiet" hours (4 a.m. to 9 a.m., 2 p.m. to 7 p.m.) (36 – 40 weeks gestation)

Time (h)	Type	Duration					Time (h)	Duration
		Oscillation type		Fetal movements		Recording		Oscillation type		Fetal movements		Recording
		Min.	Sec.	Min.	Sec.	Min.		Min.	Sec.	Min.	Sec.	Min.
4–5	I	-	20 ± 0.2	-	-	54 ± 0.3	14–15	-	10 ± 0.2	-	-	40 ± 0.4
	II	16 ± 0.3	-	-	50 ± 0			3 ± 0.4	-	-	50 ± 0.1
	III	20 ± 0.2	-	-	-			30 ± 0.4	-	-	-
	IV	18 ± 0.2	-	-	-			7 ± 0.1	-	-	-
5–6	I	-	-	1 ± 0.1	-	46 ± 0.2	15–16	1 ± 0.2	-	-	-	54 ± 0.3
	II	7 ± 0.4	-	-	-			7 ± 0.2	-	2 ± 0.1	-
	III	30 ± 0.3	-	-	-			24 ± 0.1	-	-	-
	IV	9 ± 0.3	-	-	-			21 ± 0.2	-	-	-
6–7	I	-	30 ± 0.2	-	-	59 ± 0.2	16–17	-	20 ± 0.3	-	-	45 ± 0.1
	II	18 ± 0.1	-	1	30 ± 0.3			12 ± 0.1	-	1 ± 0.3	-
	III	26 ± 0.1	-	-	-			21 ± 0.1	-	-	-
	IV	15 ± 0.2		-	-			11 ± 0.1	-	-	-
7–8	I	-	50 ± 0.1	-	-	50 ± 0.5	17–18	-	20 ± 0.1	-	-	45 ± 0.3
	II	12 ± 0.4	-	-	-			8 ± 0.2	-	1	50 ± 0.1
	III	22 ± 0.4	-	1	5 ± 0.1			20 ± 0.1	-	-	-
	IV	15 ± 0.3	-	-	-			16 ± 0.1	-	-	-
8–9	I	-	20 ± 0.1	-	-	40 ± 0.2	18–19	-	10 ± 0.1	-	-	42 ± 0.1
	II	-	-	-	50 ± 0.1			4 ± 0.3	-	-	40 ± 0.2
	III	28 ± 0.3	-	-	-			25 ± 0.2	-	-	-
	IV	12 ± 0.3	-	-	-			12 ± 0.3	-	-	-