Table 4. Meta-analysis of neonatal mortality outcomes by birth weight, gestational age, weight for gestational age, and stratified by weight for gestational age.

Outcome	Live Births	Deaths	Mortality Ratea	95% CI	ORb		Distribution of Births	Distribution of Deaths	Attributable Risk Percentc
					OR	95% CI
All	4,843	87	18.0	14.2–21.7	—	—	100%	100%	—
Birth weight
≥2,500 g	4,398	51	11.6	8.4–14.8	Ref	—	90.9	58.6	Ref
<2,500 g	445	36	80.9	55.4–106.3	7.6	4.80–12.2	9.2	41.3	85.7
Gestational age
≥37 wk	4,649	60	12.9	9.7–16.1	Ref	—	96.1	68.9	Ref
34–36 wk	156	9	57.7	20.7–94.7	6.2	3.0–12.8	3.2	10.3	77.6
<34 wk	38	18	473.6	307.3–640	58.7	28.4–121.4	0.8	20.7	97.3
Weight for gestational age
Appropriate for gestational age	3,854	57	15.0	11.0–18.6	Ref	—	79.6	66.3	Ref
Small for gestational age	989	29	29.3	18.8–39.9	2.1	1.3–3.5	20.5	33.7	49.5
Stratified by weight for gestational age
Appropriate for gestational age
≥37 wk	3,718	42	11.0	7.7–14.4	Ref	—	76.7	48.3	Ref
34–36 wk	106	2	18.8	−7.3 to 44.3	3.18	1.0–10.7	2.2	2.3	41.5
<34 wk	30	14	466.7	277.2–656.1	74.9	32.6–171.7	0.6	16.1	97.6
Small for gestational age
≥37 wk	934	19	20.3	11.3–29.4	2.23	1.2–4.10	19.3	21.8	45.8
34–36 wk	48	7	145.8	42.2–249.4	19.88	8.3–47.5	1.0	8.0	92.5
<34 wk	7	3	428.6	−65.8 to 922.9	56.97	11.1–291.7	0.1	3.4	97.4

^aNRM expressed per 1,000 live births.

^bCalculated from fixed effects meta-analysis, using Mantel-Haenszel methods for pooled ORs.

^cAttributable risk percent calculated as the observed mortality that could be attributed to different weight for gestational age outcomes.