Table 3 Multivariate logistic model for identifying factors associated with PE risk

Maternal RTL

118.13

22.20–628.65

 < 0.001

Maternal mtDNA-CN

1.1

1.01–1.20

0.032

Maternal age (Ref: < 25)

 25 ~ 29

0.99

0.39–2.57

0.992

 30 ~ 34

0.89

0.33–2.43

0.824

  >  = 35

0.82

0.26–2.65

0.744

Education(Ref: low)

 Middle

0.6

0.31–1.14

0.12

 High

0.5

0.25–1.01

0.054

Gravidity

1.22

0.90–1.67

0.204

Parity

1.03

0.46–2.33

0.935

Folic acid intake(Ref: none)

 Sometimes

0.57

0.24–1.35

0.204

 Nearly everyday

0.59

0.27–1.28

0.183

Threatened abortion(Ref: no)

3.06

1.53–6.13

0.002

Exercise(Ref: none)

 1–2 times per week

1.47

0.79–2.75

0.222

 3–4 times per week

1.66

0.74–3.72

0.216

 5–7 times per week

1.44

0.52–4.01

0.481

Second hand smoking(Ref: none)

 Less than 0.5 h a day

1.38

0.74–2.56

0.314

 0.5–1 h a day

3.05

1.24–7.51

0.016

 More than 1 h a day

1.82

0.58–5.67

0.302

BMI at delivery

1.05

0.99–1.12

0.114