Low-intensity ultrasound promotes uterine involution after cesarean section: the first multicenter, randomized, controlled clinical trial

Figures & data

Figure 1. (A) The therapeutic process of LIUS; (B)The method to measure the fundal height.

Figure 2. Flow diagram for subject selection.

Table 1. Baseline demographic and clinical characteristics (FAS).

Index	LIUS group	Control group	t Value	p Value
Age	30.19 ± 4.33	29.57 ± 4.11	1.53	0.1280
Height	160.28 ± 4.62	159.76 ± 4.57	1.19	0.2332
Weight	69.92 ± 8.20	68.76 ± 9.16	1.40	0.1633
BMI	27.22 ± 2.97	26.92 ± 3.04	1.05	0.2929
Systolic pressure	114.21 ± 11.38	114.08 ± 11.33	0.12	0.9072
Diastolic pressure	72.80 ± 8.80	73.43 ± 8.44	−0.77	0.4435
Heart rate	87.43 ± 11.39	86.58 ± 9.55	0.86	0.3924△
Intraoperative Bleeding volume	255.80 ± 91.37	255.51 ± 76.54	0.04	0.9709△
Parity	1.18 ± 0.40	1.16 ± 0.39	0.38	0.7021
Infant birth weight	3477.38 ± 431.93	3440.74 ± 484.30	0.84	0.4020

△: Satterthwaite t’ test when variance was not homogeneous; BMI: body mass index.

Figure 3. (A) FAS; (B) PPS. Fundal height changes in both groups of subjects before and after five treatments. (C) FAS; (D) PPS. Fundal height difference between the two groups of subjects before and after five treatments. (a) After ultrasound treatment; (b) before ultrasound treatment.

Table 2. Comparison of repeated measurement of uterine height before and after five treatments between the two groups of subjects.

Testing effect	FAS		PPS
	F value	p Value	F value	p Value
Group	15.39	0.0001	15.91	<0.0001
Time	420.92	<0.0001	495.60	<0.0001
Group*Time	25.66	<0.0001	37.76	<0.0001

Note. Greenhouse-Geisser correction.

Figure 4. Comparison of the effect of uterine involution between the two groups of subjects. Good uterine involution, the total duration of lochia? 42 days; Poor uterine involution, the total duration of lochia >42 days.

Table 3. Comparison of the total duration of lochia and the duration of bloody lochia between the two groups of subjects (PPS).

Index	Group	mean value ± SD	median(minimum, maximum)	t Value	p Value
Total duration of lochia, days	LIUS group	29.88 ± 7.53	30.00 (16.00, 45.00)	−5.06	<0.0001△
	Control group	34.46 ± 9.84	37.00 (21.00, 62.00)
Duration of bloody lochia, days	LIUS group	5.76 ± 2.98	5.00 (2.00, 16.00)	−3.72	0.0002△
	Control group	7.06 ± 3.72	6.00 (2.00, 22.00)

△, Satterthwaite t’ test when variance was not homogeneous.

Figure 5. (A) FAS; (B) PPS. Pain VAS scores changes in both groups of subjects before and after five treatments. (C) FAS; (D) PPS. Pain VAS scores difference between the two groups of subjects before and after five treatments. (a) After ultrasound treatment; (b) before ultrasound treatment.

Table 4. Comparison of repeated measurement of VAS scores before and after five treatments between the two groups of subjects.

Testing effect	FAS		PPS
	F value	p Value	F value	p Value
Group	55.16	0.0001	96.55	<0.0001
Time	277.82	<0.0001	307.91	<0.0001
Group*Time	194.45	<0.0001	231.45	<0.0001

Note. Greenhouse-Geisser correction.