Advances in Epidemiology / 2015 / Article / Tab 4

Research Article

Survival of Preterm Singleton Deliveries: A Population-Based Retrospective Study

Table 4

Adjusted hazards ratios (HR) for the association between pregnancy risk factors and early mortality among singletons, Missouri, 1978–2005.

Predictor Neonatal death Postneonatal deathInfant death
HR (CI)HR (CI)HR (CI)

Marital status
 Married1.001.001.00
 Unmarried 0.88 (0.78–0.99)1.27 (1.12–1.45)1.02 (0.94–1.12)
Maternal age
 Less than 18 yrs1.13 (0.89–1.43)0.95 (0.72–1.25)1.02 (0.85–1.22)
 18–35 years1.001.001.00
 More than 35 years0.99 (0.86–1.16)0.89 (0.71–1.12)0.97 (0.86–1.10)
Maternal race
 White0.97 (0.86–1.10)0.77 (0.65–0.90)0.90 (0.81–0.99)
 Black 1.001.001.00
 Other 1.02 (0.73–1.43)0.60 (0.37–0.97)0.83 (0.63–1.09)
Infant sex
 Female 0.85 (0.78–0.93)0.69 (0.62–0.77)0.79 (0.74–0.84)
 Male 1.001.001.00
Maternal educational
 Less than 12 years1.001.001.00
 12 years or more0.91 (0.80–1.04)0.79 (0.69–0.92)0.86 (0.78–0.94)
Paternal educational
 Less than 12 yrs1.001.001.00
 12 years or more0.86 (0.76–0.97)0.69 (0.61–0.80)0.79 (0.72–0.86)
Maternal smoking
 Yes0.90 (0.81–1.00)1.69 (1.50–1.91)1.17 (1.08–1.27)
 No 1.001.001.00
Type of delivery
 Caesarean section 1.53 (1.40, 1.68)1.39 (1.22, 1.58)1.37 (1.27, 1.48)
 Vaginal birth1.001.001.00
Gestational age (week)0.87 (0.86–0.89)1.07 (1.04–1.10)0.91 (0.90–0.93)
Birth weight (gram)0.9992 (0.9991–0.9993)0.9992 (0.999–0.9993)0.9992 (0.9992–0.9993)