Table 2.
Risk of neonatal outcomes associated with maternal age categories (versus aged 20–24 years).
| Outcome | Maternal age | Women with complete data (n = 30,831) | ||
|---|---|---|---|---|
| Crude RR | Multivariate model 1a | Multivariate model 2b | ||
| Preterm birth (<37weeks) | ||||
| All adolescents | 1.09 (1.00–1.18) | 1.17 (1.08–1.27) | 1.16 (1.07–1.26) | |
| Junior adolescent | 1.14 (0.74–1.74) | 1.22 (0.81–1.82) | 1.18 (0.79–1.76) | |
| Senior adolescent | 1.09 (1.00–1.18) | 1.17 (1.08–1.27) | 1.15 (1.06–1.25) | |
| Very preterm birth (<32weeks) | ||||
| All adolescents | 1.18 (0.99–1.39) | 1.32 (1.11–1.56) | 1.31 (1.10–1.55) | |
| Junior adolescent | 1.02 (0.39–2.67) | 1.12 (0.45–2.80) | 1.08 (0.43–2.72) | |
| Senior adolescent | 1.18 (1.00–1.40) | 1.33 (1.12–1.57) | 1.31 (1.10–1.55) | |
| Extremely preterm birth (<28weeks) | ||||
| All adolescents | 1.30 (0.99–1.70) | 1.39 (1.06–1.83) | 1.39 (1.06–1.83) | |
| Junior adolescent | 1.39 (0.35–5.51) | 1.46 (0.37–5.71) | 1.42 (0.36–5.55) | |
| Senior adolescent | 1.29 (0.98–1.70) | 1.39 (1.05–1.84) | 1.38 (1.04–1.82) | |
| Small for gestational age | ||||
| All adolescents | 0.92 (0.80–1.07) | 0.92 (0.79–1.07) | 0.88 (0.76–1.03) | |
| Junior adolescent | 0.96 (0.44–2.09) | 0.90 (0.42–1.94) | 0.82 (0.38–1.77) | |
| Senior adolescent | 0.92 (0.79–1.07) | 0.92 (0.79–1.07) | 0.89 (0.76–1.03) | |
| Low birth weight | ||||
| All adolescents | 1.05 (0.98–1.13) | 1.08 (1.01–1.15) | 1.05 (0.98–1.12) | |
| Junior adolescent | 1.05 (0.73–1.50) | 1.03 (0.74–1.44) | 0.97 (0.69–1.35) | |
| Senior adolescent | 1.05 (0.98–1.13) | 1.08 (1.01–1.15) | 1.05 (0.98–1.12) | |
| Low Apgar (5 min, <7) | ||||
| All adolescents | 1.37 (1.12–1.67) | 1.41 (1.15–1.73) | 1.41 (1.16–1.73) | |
| Junior adolescent | 2.00 (0.84–4.73) | 2.06 (0.87–4.89) | 2.03 (0.85–4.84) | |
| Senior adolescent | 1.35 (1.10–1.66) | 1.39 (1.13–1.71) | 1.39 (1.13–1.71) | |
| IUFD/Early neonatal death | ||||
| All adolescents | 1.03 (0.69–1.52) | 1.06 (0.71–1.59) | 1.07 (0.71–1.60) | |
| Junior adolescent | none | — | — | |
| Senior adolescent | 1.06 (0.71–1.57) | 1.10 (0.73–1.64) | 1.09 (0.73–1.64) | |
Junior adolescent: Women aged ≤15.
Senior adolescent: Women aged 16–19.
All adolescent: Women aged ≤19.
aAdjusted by parity, pre-pregnancy BMI, gestational weight gain, maternal smoking, pre-existing hypertension, pre-existing diabetes or gestational diabetes, and year of delivery.
bAdjusted by parity, pre-pregnancy BMI, gestational weight gain, maternal smoking, preexisting hypertension, preexisting diabetes or gestational diabetes, year of delivery, and maternal height.