Table 1 Characteristics of the participants (n = 1515)

Age (years), n (%)

  < 25

60 (4.0)

 25–29

560 (37.0)

 30–34

673 (44.4)

  ≥ 35

222 (14.7)

Ethnicity, n (%)

 Han

1491 (98.4)

 Minorities

24 (1.6)

Level of education, n (%)

 High school or less

109 (7.2)

 College

1002 (66.1)

 Professional or graduate

404 (26.7)

Current employment status, n (%)

 Does not work

428 (28.3)

 On duty

1087 (71.7)

Personal monthly income, n (%)^a

  < ¥10,000

368 (24.3)

  ≥ ¥10,000

1147 (75.7)

Pre-pregnancy body mass index, n (%)

 Underweight

213 (14.1)

 Normal weight

1029 (67.9)

 Overweight

225 (14.9)

 Obese

48 (3.2)

Family support, n (%), yes

1452 (95.8)

Friends support, n (%), yes

1425 (94.1)

Medical workers support, n (%), yes

1338 (88.3)

Regular exercise before pregnancy, n (%), yes

674 (44.5)

Active or passive smoking before pregnancy, n (%), yes

198 (13.1)

Alcohol drinking before pregnancy, n (%), yes

150 (9.9)

History of spontaneous abortions, n (%), yes

236 (15.6)

Parity, n (%)

 Primiparous

1233 (81.4)

 Multiparous

282 (18.6)

Current stage of pregnancy, n (%)

 First trimester: ≤ 13 + 6 weeks

668 (44.1)

 Second trimester:14–27 + 6 weeks

389 (25.7)

 Third trimester: ≥ 28 weeks

458 (30.2)

Singleton pregnancy, n (%), yes

1499 (98.9)

Nausea and vomiting during pregnancy, n (%), yes

1202 (79.3)

Measures taken to prevent miscarriage, n (%), yes

612 (40.4)

Gestational diabetes, n (%), yes

58 (3.8)

Poor prenatal sleep quality, n (%), yes

639 (42.2)

Prenatal anxiety, n (%), yes

114 (7.5)

Prenatal depression, n (%), yes

391 (25.8)