Table 3 Univariate analysis of antenatal and perinatal risk factors for postpartum depressive symptoms^a

[A] Antenatal risk factors

 Maternal age, years

  < 35 (84)

13 (86.7)

66 (61.1)

0.082

  ≥ 35 (45)

2 (13.3)

42 (38.9)

 Primiparous (78)

11 (73.3)

62 (57.4)

0.276

 Mode of conception

  Natural conception/Timed intercourse (117)

15 (100)

96 (88.9)

0.358

  Artificial insemination/In-vitro fertilization (12)

0 (0)

12 (11.1)

 Education

  University or graduate school (83)

10 (66.7)

70 (64.8)

0.616

  Junior college or technical school (21)

3 (20.0)

16 (14.8)

  High school (4)

1 (6.7)

3 (2.8)

  Others (6)

0 (0)

6 (5.6)

 Smoking before pregnancy

  No (116)

12 (80.0)

98 (90.7)

0.167

  Yes (12)

3 (20.0)

9 (8.3)

 Alcohol before pregnancy

  No (25)

3 (20.0)

21 (19.4)

0.245

  Occasionally (91)

9 (60.0)

77 (71.3)

  Almost every day (11)

3 (20.0)

8 (7.4)

 Family type

  Nuclear family (120)

14 (93.3)

100 (92.6)

0.559

  Extended family (6)

1 (6.7)

5 (4.6)

 Family history of mental illness (21)

7 (46.7)

13 (12.0)

0.004

 Regular exercise at second trimester (34)

7 (46.7)

25 (23.2)

0.064

 Working at second trimester (99)

13 (86.7)

84 (77.8)

0.736

 Family support

  No (5)

0 (0)

4 (3.7)

1

  Yes (116)

13 (86.7)

98 (90.7)

[B] Perinatal risk factors

 Preterm delivery, < 37 weeks (6)

0 (0)

4 (3.7)

1

 Final mode of delivery

  Normal vaginal delivery (90)

15 (100.0)

72 (66.7)

0.102

  Vacuum or forceps delivery (14)

0 (0)

13 (12.0)

  Cesarean section (25)

0 (0)

23 (21.3)

 Painless delivery (46)

7 (46.7)

37 (34.3)

0.395

 Pregnancy and delivery complications, total (49)

2 (13.3)

43 (39.8)

0.050

  Weak pain or prolonged labor (22)

0 (0)

22 (20.3)

  Non-reassuring fetal status (7)

0 (0)

7 (6.5)

  Hypertensive disorders of pregnancy (5)

1 (6.7)

3 (2.8)

  Atonic postpartum hemorrhage (5)

1 (6.7)

3 (2.8)

  Fetal abnormality found postpartum (2)

0 (0)

1 (0.9)

  Uterine infection (1)

0 (0)

0 (0)

  Others (7)

0 (0)

7 (6.5)