Risk/preventive factors Strata-gestational age (weeks) Extremely preterm: 24–28 weeks Very preterm: 29–32 weeks Late preterm: 33–36 weeks Full term: 37 + weeks (
= 1,403) (
= 2,910) (
= 17,592) (
= 120,112)
aOR 95% CI aOR 95% CI aOR 95% CI aOR 95% CI Maternal race: black 0.78 0.50, 1.22 1.07 0.82, 1.41 1.23 1.10, 1.37 2.18 2.09, 2.29 Maternal race: white 1.00 1.00 1.00 1.00 Maternal age: ≤19 0.41 0.20, 0.85 0.69 0.47, 1.01 0.93 0.79, 1.10 0.98 0.92, 1.05 Maternal age: 20–34 1.00 1.00 1.00 1.00 Maternal age: ≥35 0.92 0.50, 1.69 1.42 1.05, 1.93 0.99 0.87, 1.14 1.10 1.03, 1.17 Maternal education: <12 0.95 0.54, 1.67 0.97 0.70, 1.36 0.72 0.63, 0.83 1.14 1.07, 1.20 Maternal education: ≥12 1.00 1.00 1.00 1.00 Medicaid: yes 1.20 0.77, 1.88 1.05 0.80, 1.39 0.89 0.79, 0.99 1.17 1.11, 1.22 Medicaid: no 1.00 1.00 1.00 1.00 Inadequate PNC: yes 0.91 0.57, 1.47 0.88 0.64, 1.21 0.84 0.72, 0.98 1.25 1.18, 1.32 Adequate PNC 1.00 1.00 1.00 1.00 Inadequate weight gain: no 1.76 1.10, 2.80 1.74 1.29, 2.36 1.60 1.41, 1.81 2.11 2.01, 2.21 Adequate weight gain 1.00 1.00 1.00 1.00 Parity: nulliparous 0.97 0.60, 1.56 1.39 1.06, 1.83 1.28 1.14, 1.44 1.42 1.35, 1.49 Parity: primiparous 1.00 1.00 1.00 1.00 Parity: multiparous 0.61 0.36, 1.04 0.60 0.44, 0.82 1.06 0.94, 1.19 0.94 0.89, 0.99 Smoking: yes 0.95 0.53, 1.70 1.08 0.77, 1.51 1.60 1.40, 1.82 2.08 1.97, 2.20 Smoking: no 1.00 1.00 1.00 1.00 Diabetes: yes 1.17 0.43, 3.18 0.78 0.47, 1.31 0.72 0.59, 0.89 0.66 0.59, 0.74 Diabetes: no 1.00 1.00 1.00 1.00 Chronic hypertension: yes 0.64 0.18, 2.21 1.69 1.03, 2.76 1.12 0.88, 1.44 1.46 1.27, 1.68 Chronic hypertension: no 1.00 1.00 1.00 1.00 Preeclampsia: yes 3.41 2.11, 5.52 2.10 1.62, 2.72 2.82 2.52, 3.16 2.19 2.04, 2.36 Preeclampsia: no 1.00 1.00 1.00 1.00