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Table 2 Risk of adverse outcomes associated with maternal age categories (versus aged 30–34 years)

From: Association between very advanced maternal age and adverse pregnancy outcomes: a cross sectional Japanese study

Outcome

Maternal age

Main analysis (n = 365,417)

Women with complete data (n = 183,084)

Crude RR

Multivariate RRa

Multivariate RRa

Cesarean section

35–39

1.24 (1.23–1.25)

1.20 (1.18–1.21)

1.18 (1.17–1.20)

40–44

1.53 (1.51–1.56)

1.42 (1.39–1.44)

1.40 (1.37–1.43)

45–49

1.93 (1.82–2.05)

1.70 (1.60–1.80)

1.53 (1.40–1.70)

p for trend

<0.001

<0.001

<0.001

Emergency cesarean section

35–39

1.15 (1.13–1.17)

1.16 (1.14–1.18)

1.17 (1.14–1.19)

40–44

1.44 (1.40–1.48)

1.37 (1.33–1.40)

1.38 (1.33–1.43)

45–49

1.77 (1.58–1.99)

1.54 (1.37–1.73)

1.60 (1.35–1.90)

p for trend

<0.001

<0.001

<0.001

Preeclampsia

35–39

1.23 (1.18–1.28)

1.23 (1.19–1.29)

1.26 (1.19–1.34)

40–44

1.52 (1.43–1.62)

1.44 (1.35–1.53)

1.48 (1.35–1.63)

45–49

2.21 (1.70–2.87)

1.86 (1.43–2.42)

2.26 (1.57–3.25)

p for trend

<0.001

<0.001

<0.001

Severe-preeclampsia

35–39

1.22 (1.14–1.31)

1.24 (1.15–1.33)

1.26 (1.14–1.39)

40–44

1.50 (1.35–1.67)

1.42 (1.27–1.59)

1.45 (1.24–1.70)

45–49

2.41 (1.56–3.73)

2.03 (1.31–3.13)

1.91 (1.00–3.67)

p for trend

<0.001

<0.001

<0.001

Placenta previa

35–39

1.37 (1.31–1.44)

1.30 (1.24–1.37)

1.20 (1.11–1.30)

40–44

1.64 (1.52–1.77)

1.46 (1.35–1.58)

1.38 (1.22–1.55)

45–49

2.54 (1.87–3.44)

2.17 (1.60–2.95)

1.92 (1.16–3.17)

p for trend

<0.001

<0.001

<0.001

Abruption

35–39

1.09 (1.02–1.17)

1.06 (0.99–1.14)

1.11 (0.99–1.25)

40–44

1.06 (0.94–1.20)

1.02 (0.90–1.16)

1.12 (0.92–1.38)

45–49

1.39 (0.79–2.44)

1.31 (0.75–2.31)

1.24 (0.47–3.29)

p for trend

0.027

0.179

0.068

Preterm birth (<37w)

35–39

1.06 (1.04–1.08)

1.03 (1.01–1.05)

1.04 (1.01–1.07)

40–44

1.15 (1.11–1.18)

1.08 (1.05–1.11)

1.09 (1.04–1.14)

45–49

1.33 (1.15–1.54)

1.20 (1.04–1.39)

1.12 (0.89–1.40)

p for trend

<0.001

<0.001

<0.001

Very preterm birth (<32w)

35–39

1.06 (1.02–1.10)

1.02 (0.98–1.07)

1.03 (0.96–1.10)

40–44

1.10 (1.03–1.18)

1.03 (0.96–1.11)

1.04 (0.93–1.15)

45–49

1.05 (0.73–1.50)

0.94 (0.66–1.33)

0.80 (0.43–1.49)

p for trend

<0.001

0.263

0.449

Extremely preterm birth (<28w)

35–39

1.01 (0.95–1.08)

0.96 (0.89–1.04)

0.97 (0.87–1.09)

40–44

0.93 (0.82–1.05)

0.95 (0.75–0.96)

0.87 (0.72–1.05)

45–49

0.81 (0.40–1.61)

0.70 (0.35–1.40)

0.23 (0.03–1.60)

p for trend

0.476

0.017

0.139

Low birthweight

35–39

1.01 (1.00–1.03)

1.02 (1.00–1.04)

1.03 (1.01–1.06)

40–44

1.08 (1.05–1.11)

1.08 (1.05–1.11)

1.09 (1.05–1.14)

45–49

1.22 (1.08–1.39)

1.17 (1.03–1.33)

1.19 (0.99–1.44)

p for trend

<0.001

<0.001

<0.001

Small for gestational age

35–39

1.00 (0.97–1.03)

1.01 (0.98–1.04)

1.02 (0.98–1.07)

40–44

1.13 (1.07–1.20)

1.13 (1.07–1.19)

1.08 (1.00–1.17)

45–49

1.27 (0.97–1.65)

1.20 (0.92–1.57)

1.31 (0.90–1.91)

p for trend

0.001

0.001

0.035

Low Apgar (5 min, <7)

35–39

1.05 (1.00–1.09)

1.02 (0.97–1.07)

1.03 (0.95–1.10)

40–44

1.12 (1.03–1.21)

1.06 (0.98–1.15)

1.09 (0.97–1.24)

45–49

1.11 (0.73–1.68)

1.03 (0.68–1.56)

0.59 (0.25–1.40)

p for trend

0.002

0.169

0.255

Low pH of umbilical cord artery (<7.1)

35–39

1.11 (1.03–1.20)

1.13 (1.05–1.22)

1.11 (1.00–1.23)

40–44

1.28 (1.13–1.45)

1.28 (1.13–1.46)

1.25 (1.06–1.48)

45–49

1.41 (0.76–2.62)

1.35 (0.73–2.51)

1.18 (0.49–2.84)

p for trend

<0.001

<0.001

0.003

Perinatal death

35–39

0.97 (0.90–1.06)

0.98 (0.90–1.07)

1.01 (0.89–1.15)

40–44

1.08 (0.94–1.24)

1.10 (0.96–1.27)

1.06 (0.85–1.32)

45–49

1.65 (0.92–2.98)

1.70 (0.94–3.07)

1.51 (0.57–4.02)

p for trend

0.498

0.324

0.555

  1. aAdjusted by pre-pregnancy BMI, maternal height, gestational weight gain, conception method, maternal smoking during pregnancy, parity, preexisting hypertension, and preexisting diabetes or GDM