Table 3 Analysis results on influencing factors of fetal loss by univariate conditional logistic regression model

 Postgraduate or above

11 (4.60)

69 (14.44)

1.00

–

 Junior high school and below

63 (26.36)

35 (7.32)

11.29

5.29–24.11

 Senior high school

39 (16.32)

34 (7.11)

7.20

3.28–15.78

 Undergraduate

126 (52.72)

340 (71.13)

2.33

1.19–4.54

Residence in a rural area

108 (45.19)

81 (16.95)

4.03

2.84–5.72

Unemployment

110 (46.03)

100 (20.92)

3.22

2.30–4.51

 18.5–23.9

167 (69.87)

381 (79.71)

1.00

–

  < 18.5

13 (5.44)

30 (6.28)

5.60

1.88–16.75

 24.0–27.9

42 (17.57)

60 (12.55)

3.47

1.32–9.10

  ≥ 28.0

17 (7.11)

7 (1.46)

5.54

2.26–13.61

  ≥ 3

152 (63.60)

297 (62.13)

1.00

–

 1

15 (6.28)

35 (7.32)

0.84

0.44–1.58

 2

72 (30.13)

146 (30.54)

0.96

0.68–1.36

  ≥ 2

37 (15.48)

40 (8.37)

1.00

–

 0

39 (16.32)

60 (12.55)

0.70

0.39–1.28

 1

163 (68.20)

378 (79.08)

0.47

0.29–0.76

Preterm birth history

13 (5.44)

3 (0.63)

9.15

2.58–32.43

Spontaneous abortion history

75 (31.38)

101 (21.13)

1.71

1.20–2.42

Stillbirth history

2 (0.84)

2 (0.42)

0.50

0.07–3.54

Congenital malformations history

10 (4.18)

9 (1.88)

0.44

0.18–1.09

Hypertensive disorders of pregnancy

22 (9.21)

4 (0.84)

12.01

4.09–35.29

Preterm premature rupture of membranes

14 (5.86)

8 (1.67)

3.66

1.51–8.84

Velamentous cord insertion

7 (2.93)

3 (0.63)

4.78

1.22–18.64

In vitro fertilization and embryo transfer

22 (9.21)

24 (5.02)

1.92

1.05–3.50

Pregestational diabetes mellitus

5 (2.09)

4 (0.84)

2.53

0.67–9.52

Gestational diabetes mellitus

23 (9.62)

37 (7.74)

1.27

0.74–2.19

Fetal growth restriction

1 (0.42)

1 (0.21)

2.00

0.13–32.18

Placenta previa

4 (1.67)

7 (1.46)

1.15

0.33–3.95

Torsion of cord

18 (7.53)

21 (4.39)

1.77

0.93–3.39