Table 2 Risk ratios (RR) (95% CI) for early neonatal mortality according to factors.
From: Maternal age and risk of early neonatal mortality: a national cohort study
Variables | Early neonatal mortality | ||
|---|---|---|---|
RR | 95% CI | ||
Maternal age (years) | |||
≤ 19 | 1.84 | 1.77 | 1.91 |
20–24 | 1.39 | 1.37 | 1.42 |
25–29 | 1.02 | 1.01 | 1.03 |
30–34 | 1.00 | ||
35–39 | 0.89 | 0.88 | 0.90 |
≥ 40 | 1.26 | 1.23 | 1.28 |
Infant gender | |||
Male | 1.17 | 1.16 | 1.18 |
Female | 1.00 | ||
Size for gestational age | |||
Small for gestational age | 1.94 | 1.92 | 1.96 |
Appropriate for gestational age | 1.00 | ||
Large for gestational age | 2.07 | 2.03 | 2.10 |
Infant weight | |||
≤ 1499 g | 14.28 | 13.78 | 14.81 |
1500–2499 g | 4.91 | 4.76 | 5.05 |
2500–3499 g | 1.88 | 1.84 | 1.93 |
3500 g + | 1.00 | ||
Gestational age | |||
≤ 28+0 weeks | 109.57 | 106.60 | 112.63 |
28+1–32+6 weeks | 19.77 | 19.29 | 20.27 |
33+0–36+6 weeks | 5.44 | 5.34 | 5.54 |
≥ 37+0 weeks | 1.00 | ||
Multiple birth | |||
Singles | 1.00 | ||
Twins or more | 1.04 | 1.03 | 1.05 |
Parity | |||
0 | 1.00 | ||
1 | 0.96 | 0.95 | 0.97 |
≥ 2 | 1.18 | 1.17 | 1.20 |
Obstetrically underserved area | |||
Yes | 1.13 | 1.12 | 1.14 |
No | 1.00 | ||
Maternal educational level | |||
High school | 1.00 | 0.99 | 1.01 |
University or above | 1.00 | ||
Maternal employment status | |||
Employed | 0.97 | 0.96 | 0.98 |
Unemployed | 1.00 | ||
Year of delivery | |||
2011 | 1.00 | ||
2012 | 0.95 | 0.94 | 0.96 |
2013 | 0.98 | 0.97 | 0.99 |
2014 | 0.93 | 0.92 | 0.95 |
2015 | 0.92 | 0.91 | 0.93 |
