Table 3.
Crude and adjusted odds ratios for adverse neonatal outcomes in groups with interpregnancy intervals
| Variables | Model 1a crude OR (95% CI) | Model 2b adjusted OR (95% CI) | Model 3c adjusted OR (95% CI) | Model 4d adjusted OR (95% CI) |
|---|---|---|---|---|
| Preterm birth | ||||
| IPI < 12 mon | 1.79 (1.37–2.35) | 1.65 (1.25–2.19) | 1.51 (1.13–2.01) | 1.51 (1.13–2.02) |
| IPI 12–23 mon | 1.20 (0.98–1.47) | 1.13 (0.92–1.39) | 1.06 (0.85–1.31) | 1.06 (0.85–1.31) |
| IPI 24–59 mon | Reference | Reference | Reference | Reference |
| IPI ≥ 60 mon | 1.26 (1.10–1.45) | 1.15 (1.00–1.34) | 1.27 (1.07–1.50) | 1.24 (1.04–1.47) |
| Low birth weight | ||||
| IPI < 12 mon | 1.96 (1.45–2.64) | 1.67 (1.22–2.28) | 1.50 (1.09–2.07) | 1.52 (1.10–2.11) |
| IPI 12–23 mon | 1.20 (0.95–1.52) | 1.08 (0.85–1.37) | 1.00 (0.78–1.27) | 1.00 (0.78–1.28) |
| IPI 24–59 mon | Reference | Reference | Reference | Reference |
| IPI ≥ 60 mon | 1.29 (1.10–1.51) | 1.19 (1.00–1.41) | 1.32 (1.08–1.61) | 1.29 (1.05–1.58) |
| Small for gestation age | ||||
| IPI < 12 mon | 1.45 (0.93–2.27) | 1.23 (0.78–1.93) | 1.13 (0.71–1.79) | 1.15 (0.71–1.84) |
| IPI 12–23 mon | 0.92 (0.65–1.31) | 0.83 (0.59–1.19) | 0.78 (0.54–1.12) | 0.77 (0.53–1.11) |
| IPI 24–59 mon | Reference | Reference | Reference | Reference |
| IPI ≥ 60 mon | 1.16 (0.93–1.45) | 1.16 (0.92–1.47) | 1.21 (0.92–1.59) | 1.18 (0.89–1.56) |
| 1-min Apgar score ≤ 7 | ||||
| IPI < 12 mon | 2.41 (1.56–3.71) | 2.13 (1.36–3.32) | 1.93 (1.23–3.04) | 1.93 (1.22–3.04) |
| IPI 12–23 mon | 1.21 (0.83–1.76) | 1.12 (0.76–1.63) | 1.03 (0.70–1.52) | 1.03 (0.70–1.52) |
| IPI 24–59 mon | Reference | Reference | Reference | Reference |
| IPI ≥ 60 mon | 1.31 (1.02–1.70) | 1.26 (0.97–1.65) | 1.46 (1.07–1.98) | 1.42 (1.04–1.94) |
Model 1: crude OR
Model 2: adjusted for maternal age at first delivery, gravidity, parity, BMI at admission for delivery, last cesarean section, and previous abortion history
Model 3: adjusted for maternal age at first delivery, gravidity, parity, BMI at admission for delivery, last cesarean section, previous abortion history, and maternal age at current delivery
Model 4: adjusted for maternal age at first delivery, gravidity, parity, BMI at admission for delivery, last cesarean section, previous abortion history, gestational diabetes mellitus, pregnancy-induced hypertension, and maternal age at current delivery
OR odds ratio, CI confidence interval, IPI interpregnancy intervals, BMI body mass index