Gestational weeks | Country | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | p-value for trend2 |
---|---|---|---|---|---|---|---|---|---|---|---|---|
22–27 | S | 0.18 | 0.22 | 0.22 | 0.22 | 0.27 | 0.15 | 0.19 | 0.20 | 0.25 | 0.26 | 0.13 |
D | 0.19 | 0.22 | 0.23 | 0.19 | 0.20 | 0.19 | 0.22 | 0.13 | 0.27 | 0.21 | 0.83 | |
N | 0.18 | 0.20 | 0.21 | 0.20 | 0.15 | 0.27 | 0.18 | 0.20 | 0.19 | 0.14 | 0.65 | |
p for homogeneity of trends: 0.37 | ||||||||||||
28–31 | S | 0.55 | 0.69 | 0.56 | 0.60 | 0.64 | 0.54 | 0.62 | 0.62 | 0.59 | 0.57 | 0.80 |
D | 0.66 | 0.67 | 0.62 | 0.67 | 0.65 | 0.57 | 0.61 | 0.63 | 0.59 | 0.66 | 0.48 | |
N | 0.53 | 0.43 | 0.40 | 0.61 | 0.38 | 0.34 | 0.35 | 0.45 | 0.35 | 0.26 | < 0.001(R)3 | |
p for homogeneity of trends: 0.0034 | ||||||||||||
32–36 | S | 5.5 | 5.3 | 5.1 | 5.2 | 5.4 | 5.5 | 5.0 | 5.3 | 5.2 | 5.6 | 0.82 |
D | 4.5 | 5.0 | 4.3 | 4.8 | 5.0 | 5.0 | 5.2 | 5.4 | 5.6 | 5.4 | < 0.001(I)4 | |
N | 4.7 | 4.5 | 4.6 | 5.1 | 4.3 | 4.4 | 4.6 | 4.7 | 4.4 | 4.4 | 0.18 | |
p for homogeneity of trends: < 0.001 | ||||||||||||
< 37 | S | 6.3 | 6.2 | 5.9 | 6.0 | 6.3 | 6.2 | 5.9 | 6.1 | 6.1 | 6.5 | 0.67 |
D | 5.3 | 5.9 | 5.2 | 5.6 | 5.9 | 5.7 | 6.0 | 6.2 | 6.5 | 6.3 | < 0.001(I) | |
N | 5.4 | 5.1 | 5.2 | 5.9 | 4.8 | 5.0 | 5.2 | 5.3 | 5.0 | 4.8 | 0.018 (R) | |
p for homogeneity of trends: < 0.001 |