From: Trends in gestational age and birth weight in Chile, 1991–2008. A descriptive epidemiological study
Period | 1991-1995 | 1996-2000 | 2001-2008 | P1a | P2 | P3 | P1P2 | P2P3 | P1P3 | Overall Trend | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Total population | 1 344 067 | 1 253 164 | 1 870 502 | ||||||||||
N = 4 467 733 | |||||||||||||
Birth weighte | Rate % | 95% CIb | % change | P c | % change | P | % change | P | P d | ||||
<1500 | 0.61 | 0.72 | 0.88 | [0.60-0.62] | [0.70-0.73] | [0.87-0.90] | 18 | < 0.000 | 22.2 | < 0.000 | 44.3 | < 0.000 | < 0.000 |
1500-2499 | 4.02 | 3.99 | 4.39 | [4.00-4.05] | [3.95-4.02] | [4.36-4.41] | −0.7 | < 0.000 | 10.0 | < 0.000 | 9.2 | < 0.000 | 0.126 |
2500-3999 | 87.27 | 86.43 | 86.01 | [87.22-87.33] | [86.37-86.49] | [85.96-86.06] | −1.0 | < 0.000 | −0.5 | < 0.000 | −1.4 | < 0.000 | < 0.000 |
4000-max | 8.10 | 8.86 | 8.72 | [8.05-8.15] | [8.80-8.90] | [8.68-8.77] | 9.4 | < 0.000 | −1.6 | < 0.000 | 7.7 | 0.00 | 0.190 |
Singletons | (1 323 021) | (1 232 824) | (1 836 582) | ||||||||||
(4 392427) | |||||||||||||
<1500 | 0.53 | 0.62 | 0.75 | [0.52-0.54] | [0.60-0.63] | [0.74-0.76] | 17.0 | < 0.000 | 21.0 | < 0.000 | 41.5 | < 0.000 | < 0.000 |
1500-2499 | 3.44 | 3.38 | 3.65 | [3.42-3.48] | [3.35-3.41] | [3.60-3.70] | −1.7 | < 0.000 | 8.0 | < 0.000 | 6.1 | < 0.000 | 0.274 |
2500-3999 | 87.80 | 87.00 | 86.70 | [87.74-87.85] | [86.94-87.06] | [86.64-86.77] | −0.9 | 0.000 | −0.3 | < 0.000 | −1.3 | < 0.000 | 0.003 |
4000-max | 8.23 | 9.00 | 8.90 | [8.17-8.27] | [8.95-9.05] | [8.83-8.92] | 9.4 | < 0.000 | −1.1 | < 0.000 | 8.1 | 0.000 | 0.176 |
Multiples (75 306) | (21 046) | (20 340) | (33 920) | ||||||||||
<1500 | 5.53 | 6.70 | 7.89 | [5.20-5.80] | [6.40-6.90] | [7.60-8.20] | 21.2 | < 0.000 | 17.8 | < 0.000 | 42.7 | < 0.000 | < 0.000 |
1500-2499 | 39.87 | 40.77 | 44.43 | [39.20-40.53] | [40.09-41.44] | [43.90-45.02] | 2.3 | 0.01 | 9.0 | < 0.000 | 11.4 | < 0.000 | 0.006 |
2500-3999 | 54.38 | 52.37 | 47.52 | [53.71-55.06] | [51.69-53.06] | [47.00-48.05] | −3.7 | < 0.000 | −9.3 | < 0.000 | −12.6 | < 0.000 | < 0.001 |
4000-max | 0.22 | 0.16 | 0.15 | [0.16-0.28] | [0.10-0.21] | [0.11-0.19] | −27.3 | < 0.000 | −6.3 | < 0.000 | −31.8 | <0.000 | 0.560 |