Table 4 Crude and adjusted Odds ratios (95% confidence intervals) for maternal and neonatal outcomes at advanced and very advanced maternal age groups compared with < 35 years group

Gestational diabetes

1.15 (1.01–1.27) p < 0.15

1.21 (0.82–1.27) p < 0.01

2.41 (2.13–3.76) p < 0.15

2.23 (0.25–3.96) p < 0.01

Gestational hypertension

1.57 (1.16–2.07) p < 0.15

1.55 (1.32–1.78) p < 0.01

1.70 (1.12–2.63) p < 0.15

1.68 (0.69–4.16) p < 0.01

Pre-eclampsia

1.26 (1.15–1.39) p < 0.15

1.34 (1.11–1.62) p < 0.01

1.44 (1.21–1.67) p < 0.15

1.37 (1.13–1.48) p < 0.01

Ablatio placenta

1.00 (0.63–1.57) p = 0.99

1.00 (0.42–1.68) p = 1.00

1.00 (0.39–2.64) p = 1.00

1.03 (0.91–1.12) p = 0.88

Spontaneous preterm delivery before 34 weeks

0.86 (0.68–0.98) p < 0.15

0.90 (0.75–1.16) p = 0.03

1.35 (0.95–1.91) p < 0.15

1.33 (1.21–1.49) p = 0.24

Spontaneous late preterm delivery between 34 and 37 weeks of gestation

0.61 (0.29–1.32) p = 0.20

0.82 (0.72–1.08) p = 0.35

1.22 (1.10–1.64) p < 0.15

1.41 (1.29–1.57) p < 0.01

Prolonged rupture of

Membranes

0.87 (0.85–0.91) p = 0.78

0.91 (0.71–1.15) p = 0.81

0.83 (0.72–0.95) p = 0.94

1.05 (0.72–1.08) p = 0.98

SGA (<10th centile)^b

1.71 (1.44–2.49) p < 0.15

1.65 (0.71–3.05) p < 0.01

1.63 (1.38–2.11) p < 0.15

1.55 (1.41–1.88) p < 0.01

LGA (>90th centile)^b

1.10 (0.93–1.32) p = 0.27

1.12 (0.81–1.52) p = 0.35

0.68 (0.34–1.37) p = 0.27

0.54 (0.50–0.64) p = 0.11

Placenta previa

1.00 (0.84–1.23) p = 0.95

1.05 (0.81–1.15) p = 0.88

0.78 (0.66–0.98) p = 0.15

1.03 (0.76–1.34) p = 0.25

Post-term pregnancy

1.05 (0.75–1.54) p = 0.61

1.02 (0.74–1.67) p = 0.77

0.68 (0.45–1.03) p = 0.21

0.54 (0.41–0.67) p = 0.18

Operative vaginal delivery

0.72 (0.46–1.18) p = 0.19

0.68 (0.51–0.88) p = 0.34

0.81 (0.72–0.96) p = 0.15

0.73 (0.56–0.94) p = 0.33

Cesarean delivery

1.75 (1.61–1.95) p < 0.15

1.87 (1.44–2.25) p < 0.01

2.67 (1.90–3.82) p < 0.15

2.76 (1.70–4.65) p < 0.01

Low birth weight < 2500 g

1.23 (1.08–1.41) p < 0.15

1.27 (1.14–1.59) p < 0.01

1.20 (0.84–1.23) p < 0.15

1.19 (1.09–1.35) p < 0.01

First minute APGAR score < 7

1.14 (0.91–1.49) p < 0.15

1.10 (0.73–1.56) p = 0.08

1.27 (0.95–1.71) p < 0.15

1.26 (1.01–1.55) p = 0.04

Fifth minute APGAR score < 7

0.94 (0.71–1.30) p = 0.74

1.00 (0.99–1.05) p = 0.96

1.04 (0.95–1.15) p < 0.15

1.05 (1.00–1.08) p = 0.04

Neonatal intensive care unit requirement

1.69 (1.02–2.76) p < 0.15

1.68 (1.42–2.15) p < 0.01

1.54 (1.13–2.12) p < 0.15

1.52 (1.21–1.92) p < 0.01

Neonatal morbidity

0.93 (0.27–3.10) p = 0.93

0.86 (0.70–1.09) p = 0.25

1.12 (0.82–1.55) p = 0.48

1.09 (0.90–1.33) p = 0.23