study	year	sample size		intervention measure			outcome indicator
study	year	IG	CG	IG	CG	frequency	outcome indicator
F. T. Ji [12]	2016	28	27	Oral drip of colostrum	Saline drip	Once every 4 h, 0.2 ml each time, for seven days	A, B
X. J. Zhao [13]	2017	20	20	Oral drip of colostrum	Saline drip	Once every 4 h, 0.2 ml each time, for seven days	A
C. Y. Chen [14]	2018	46	46	Oral drip of colostrum	Saline drip	Once every 4 h, 0.2 ml each time, for seven days	A, B, C, D
S. X. Cao [15]	2018	20	20	Colostrum oral smear	Sterile water smear	Once every 3 h	B, E
S. X. Cao [15]	2018	20	20	Colostrum oral smear	Sterile water smear	Once every 6 h	B, E
L. F. Chen [16]	2017	30	30	Colostrum oral smear	Normal saline smear	Once every 3 h, for two weeks	B, C, D, E
Y. X. Zhang [9]	2017	27	28	Oral drip of colostrum	Saline drip	Once every 4 h, 0.2 ml each time, For seven days	C, E, G, H
Glass K. [11]	2017	17	13	Oral drip of colostrum	Sterile drop injection	Once every 3 h, 0.2 ml each time	C, E, G, H