Table 3 Mediation effect of pregnancy-induced hypertension (PIH) in the relationship between assisted reproductive technology (ART) and adverse neonatal outcomes

Adverse neonatal outcomes

Total

1.45 (1.42–1.49)

1.47 (1.43–1.51)

1.43 (1.39–1.47)

0.31 (0.28–0.34)

1.37 (1.33–1.41)

8.51

Age < 35 years

1.43 (1.37–1.49)

1.59 (1.52–1.66)

1.55 (1.48–1.61)

0.32 (0.28–0.37)

1.38 (1.32–1.45)

6.78

Age ≥ 35 years

1.34 (1.29–1.39)

1.42 (1.37–1.47)

1.37 (1.33–1.42)

0.37 (0.33–0.41)

1.44 (1.39–1.50)

11.90

Primipara

1.41 (1.37–1.46)

1.42 (1.37–1.47)

1.37 (1.32–1.42)

0.31 (0.28–0.35)

1.37 (1.32–1.42)

11.90

Multipara

1.41 (1.36–1.47)

1.53 (1.47–1.60)

1.49 (1.43–1.56)

0.38 (0.32–0.43)

1.46 (1.38–1.54)

7.55

Low birth weight

Total

1.24 (1.19–1.30)

1.24 (1.19–1.30)

1.17 (1.12–1.23)

0.45 (0.41–0.50)

1.57 (1.51–1.64)

29.17

Age < 35 years

1.20 (1.12–1.29)

1.36 (1.26–1.45)

1.29 (1.20–1.38)

0.47 (0.40–0.54)

1.60 (1.49–1.71)

19.44

Age ≥ 35 years

1.20 (1.13–1.27)

1.21 (1.14–1.28)

1.14 (1.08–1.21)

0.51 (0.46–0.57)

1.67 (1.58–1.77)

33.33

Primipara

1.17 (1.11–1.23)

1.19 (1.13–1.26)

1.12 (1.06–1.19)

0.46 (0.41–0.51)

1.58 (1.50–1.67)

36.84

Multipara

1.15 (1.07–1.24)

1.30 (1.21–1.40)

1.24 (1.15–1.34)

0.53 (0.46–0.60)

1.70 (1.58–1.83)

20.00

Premature birth

Total

1.48 (1.44–1.53)

1.64 (1.58–1.69)

1.58 (1.53–1.64)

0.33 (0.30–0.37)

1.40 (1.35–1.44)

9.37

Age < 35 years

1.41 (1.34–1.49)

1.77 (1.68–1.86)

1.71 (1.62–1.81)

0.35 (0.30–0.40)

1.41 (1.34–1.48)

7.79

Age ≥ 35 years

1.34 (1.29–1.39)

1.56 (1.50–1.63)

1.50 (1.44–1.57)

0.38 (0.34–0.43)

1.47 (1.41–1.53)

10.71

Primipara

1.50 (1.43–1.56)

1.58 (1.51–1.65)

1.52 (1.45–1.59)

0.35 (0.31–0.39)

1.42 (1.36–1.48)

10.34

Multipara

1.52 (1.45–1.59)

1.71 (1.63–1.79)

1.66 (1.58–1.74)

0.38 (0.33–0.43)

1.46 (1.39–1.54)

7.04

NICU admission

Total

1.60 (1.55–1.66)

1.41 (1.36–1.46)

1.36 (1.32–1.41)

0.30 (0.27–0.33)

1.35 (1.31–1.38)

12.20

Age < 35 years

1.60 (1.51–1.68)

1.53 (1.44–1.61)

1.48 (1.40–1.56)

0.30 (0.26–0.35)

1.36 (1.30–1.42)

9.43

Age ≥ 35 years

1.44 (1.38–1.50)

1.42 (1.36–1.49)

1.38 (1.31–1.44)

0.35 (0.31–0.38)

1.41 (1.36–1.47)

9.52

Primipara

1.53 (1.47–1.60)

1.41 (1.35–1.48)

1.37 (1.31–1.43)

0.29 (0.25–0.32)

1.33 (1.29–1.38)

9.76

Multipara

1.48 (1.40–1.57)

1.39 (1.32–1.48)

1.35 (1.28–1.43)

0.37 (0.31–0.42)

1.44 (1.37–1.52)

10.26