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 |