Table 2 Trends of gestational-age categories, singletons and multiples live births in Chile 1991-2008
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 | ||||||||||
4 467 733 | |||||||||||||
Gestational agee | Rate % | 95% CIb | % change | P c | % change | P | % change | P | P d | ||||
<32 | 0.70 | 0.77 | 0.96 | [0.68-0.71] | [0.76-0.79] | [0.95-0.98] | 10.0 | < 0.000 | 24.7 | < 0.000 | 37.1 | < 0.000 | < 0.000 |
32-36 | 4.33 | 4.64 | 5.62 | [4.30-4.37] | [4.60-4.68] | [5.59-5.66] | 7.2 | < 0.000 | 21.1 | < 0.000 | 29.8 | < 0.000 | < 0.000 |
37-41 | 93.98 | 93.96 | 93.05 | [93.9-94.02] | [93.9-94.4.00] | [93.0-93.10] | 0.0 | 0.47 | −1.0 | < 0.000 | −1.0 | < 0.000 | 0.004 |
≥42 | 0.99 | 0.62 | 0.36 | [0.97-1.00] | [0.61-0.63] | [0.35-0.37] | −37.4 | < 0.000 | −41.9 | < 0.000 | −63.6 | < 0.000 | < 0.000 |
Singletons | (1 323 021) | (1 232 824) | (1 836 582) | ||||||||||
(4 392 427) | |||||||||||||
<32 | 0.62 | 0.67 | 0.82 | [0.60-0.63] | [0.66-0.69] | [0.81-0.84] | 8.1 | < 0.000 | 22.4 | < 0.000 | 32.3 | < 0.000 | < 0.000 |
32-36 | 3.80 | 4.04 | 4.83 | [3.76-3.83] | [4.00-4.07] | [4.80-4.86] | 6.3 | < 0.000 | 19.6 | < 0.000 | 27.1 | < 0.000 | < 0.000 |
37-41 | 94.58 | 94.66 | 93.98 | [94.5-94.62] | [94.6-94.70] | [93.9-94.01] | 0.0 | 0.48 | −0.7 | < 0.000 | −0.6 | < 0.000 | 0.020 |
≥42 | 0.99 | 0.63 | 0.37 | [0.98-1.00] | [0.62-0.64] | [0.36-0.38] | −37.0 | < 0.000 | −41.3 | < 0.000 | −63.0 | < 0.000 | < 0.000 |
Multiples (75 306) | (21 046) | (20 340) | (33 920) | ||||||||||
<32 | 5.63 | 6.84 | 8.48 | [5.30-5.90] | [6.50-7.20] | [8.20-8.80] | 21.5 | <0.01 | 24.0 | < 0.000 | 50.6 | < 0.000 | < 0.000 |
32-36 | 38.00 | 41.50 | 48.60 | [37.4-38.80] | [40.81-42.17] | [48.04-49.10] | 9.2 | <0.01 | 17.1 | < 0.000 | 27.9 | < 0.000 | < 0.000 |
37-41 | 55.80 | 51.65 | 42.93 | [55.6-56.90] | [51.00-52.34] | [42.41-43.46] | −7.5 | <0.01 | −16.9 | < 0.000 | −30.0 | < 0.000 | < 0.000 |
≥42 | 0.04 | 0.01 | 0.01 | [0.02-0.07] | [0.00-0.02] | [0.00-0.02] | −75.0 | 0.012 | 0.0 | 0.629 | −75.0 | < 0.000 | 0.623 |