TABLE 3. Mortality Rates and RRs (±95% CIs) by Gestational Age and Plurality, USA, 1983-1986
Gestation |
Fetal |
Perinatal |
Early Neonatal |
Late Neonatal |
Neonatal |
Postneonatal |
Infant |
||||||||||||||
Categories |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
Single |
Twin |
Twin RR |
(wk) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
Rate |
Rate |
(95% CI) |
28–30 |
81.0 |
37.1 |
0.48 |
136.7 |
102.9 |
0.73 |
66.7 |
68.4 |
1.03 |
21.0 |
32.0 |
1.54 |
87.7 |
100.4 |
1.16 |
31.4 |
39.8 |
1.28 |
119.1 |
140.2 |
1.21 |
|
|
|
(0.41–0.55) |
|
|
(0.66–0.79) |
|
|
(0.92–1.15) |
|
|
(1.31–1.83) |
|
|
(1.06–1.28) |
|
|
(1.01–1.48) |
|
|
(1.11–1.31) |
31–34 |
28.0 |
17.7 |
0.64 |
42.5 |
28.4 |
0.66 |
15.7 |
10.9 |
0.69 |
3.7 |
4.2 |
1.12 |
19.5 |
15.1 |
0.77 |
11.6 |
13.9 |
1.20 |
29.3 |
30.0 |
0.95 |
|
|
|
(0.59–0.70) |
|
|
(0.61–0.71) |
|
|
(0.61–0.77) |
|
|
(0.92–1.35) |
|
|
(0.77–0.85) |
|
|
(1.08–1.33) |
|
|
(0.89–1.02) |
35–38 |
4.8 |
8.3 |
1.74 |
7.2 |
11.1 |
1.55 |
2.4 |
2.8 |
1.17 |
0.9 |
1.4 |
1.48 |
3.3 |
4.1 |
1.25 |
4.1 |
6.6 |
1.60 |
7.4 |
10.7 |
1.44 |
|
|
|
(1.62–1.87) |
|
|
(1.46–1.65) |
|
|
(1.03–1.33) |
|
|
(1.24–1.77) |
|
|
(1.13–1.38) |
|
|
(1.47–1.73) |
|
|
(1.35–1.54) |
39–42 |
1.7 |
7.3 |
4.41 |
2.7 |
9.5 |
3.52 |
1.0 |
2.1 |
2.05 |
0.5 |
1.2 |
2.33 |
1.5 |
3.3 |
2.16 |
2.5 |
6.0 |
2.35 |
4.1 |
9.3 |
2.28 |
|
|
|
(3.99–4.88) |
|
|
(3.22–3.85) |
|
|
(1.70–2.47) |
|
|
(1.80–3.02) |
|
|
(1.86–2.51) |
|
|
(2.10–2.63) |
|
|
(2.08–2.50) |
CI = confidence interval; RR = relative risk.
(Luke B, Minogue J: Contribution of gestational age and birth
weight to perinatal viability in singletons versus twins. J Matern Fetal med
3:263, 1994)