Table 1.

Sociodemographic characteristics of respondents.

Characteristics	N	%
Education
<High school	173	13.7
High school	273	21.7
>High school	814	64.6
Marital status
Single	3	0.2
Living with a spouse/partner	1251	99.3
Widow/divorced	6	0.5
Occupation
Unemployed	98	7.8
Employed	1162	92.2
Location
Urban	927	73.6
Rural	321	25.5
Mountainous	11	0.9
	Mean	SD
Gestational age (weeks)	28.6	9.3
Monthly personal income (Million VND)	7.3	7.8
Monthly household income/person (Million VND)	9.8	21.9