Table 1.All live births, singleton and multiple births, singleton and multiple birth rates, and low birth weight (LBW) rate from 1995 to 2005 in the Republic of Korea
|
Year
|
|
1995 |
1996 |
1997 |
1998 |
1999 |
2000 |
2001 |
2002 |
2003 |
2004 |
2005 |
All live births |
712 750 |
657 388 |
644 103 |
639 011 |
636 389 |
634 438 |
554 581 |
489 999 |
487 849 |
471 225 |
433 429 |
Singleton births |
703 374 |
648 602 |
635 439 |
629 376 |
626 440 |
623 741 |
544 596 |
480 322 |
478 015 |
461 305 |
423 943 |
Multiple births |
9376 |
8786 |
8664 |
9635 |
9949 |
10 697 |
9985 |
9677 |
9834 |
9920 |
9486 |
Singleton birth rate (%)*
|
98.68 |
98.66 |
98.65 |
98.49 |
98.44 |
98.31 |
98.20 |
98.03 |
97.98 |
97.89 |
97.81 |
Multiple birth rate (%)*
|
1.32 |
1.34 |
1.35 |
1.51 |
1.56 |
1.69 |
1.80 |
1.97 |
2.02 |
2.11 |
2.19 |
LBW rate (%) |
|
|
|
|
|
|
|
|
|
|
|
All live births*
|
3.02 |
3.07 |
3.22 |
3.46 |
3.55 |
3.80 |
3.93 |
3.96 |
4.06 |
4.13 |
4.28 |
Singleton births*
|
2.57 |
2.58 |
2.69 |
2.80 |
2.84 |
3.02 |
3.08 |
3.03 |
3.13 |
3.15 |
3.25 |
Multiple births*
|
36.70 |
38.91 |
42.20 |
46.95 |
47.72 |
49.19 |
50.28 |
50.19 |
49.32 |
49.86 |
50.33 |
Table 2.Distribution of maternal age and parity of births in 1995 and 2005 by plurality in the Republic of Korea n (%)
Maternal age (y) |
1995
|
2005
|
p-value1
|
Birth order
|
Birth order
|
First |
Second |
≥ Third |
First |
Second |
≥ Third |
Singleton births |
|
|
|
|
|
|
< 0.001 |
- 19 |
6134 (0.87) |
692 (0.10) |
18 (< 0.01) |
1966 (0.46) |
160 (0.04) |
6 (< 0.01) |
|
20 - 24 |
102 049 (14.51) |
31 465 (4.47) |
1685 (0.24) |
24 564 (5.79) |
6522 (1.54) |
567 (0.13) |
|
25 - 29 |
191 487 (27.22) |
173 663 (24.69) |
16 682 (2.37) |
112 293 (26.49) |
53 164 (12.54) |
6037 (1.42) |
|
30 - 34 |
33 887 (4.82) |
84 000 (11.94) |
28 584 (4.06) |
68 731 (16.21) |
85 121 (20.08) |
19 736 (4.66) |
|
35 - 39 |
7253 (1.03) |
11 547 (1.64) |
10 672 (1.52) |
11 466 (2.70) |
16 559 (3.91) |
11 540 (2.72) |
|
40 - |
1139 (0.16) |
981 (0.14) |
1436 (0.20) |
1833 (0.43) |
1558 (0.37) |
2120 (0.50) |
|
Multiple births |
|
|
|
|
|
|
< 0.001 |
- 19 |
23 (0.25) |
20 (0.21) |
1 (0.01) |
5 (0.05) |
5 (0.05) |
0 (-) |
|
20 - 24 |
471 (5.02) |
803 (8.56) |
149 (1.59) |
171 (1.80) |
206 (2.17) |
43 (0.45) |
|
25 - 29 |
1221 (13.02) |
2804 (29.91) |
887 (9.46) |
1289 (13.59) |
1609 (16.96) |
370 (3.90) |
|
30 - 34 |
447 (4.77) |
1191 (12.70) |
701 (7.48) |
1490 (15.71) |
2095 (22.09) |
835 (8.80) |
|
35 - 39 |
114 (1.22) |
267 (2.85) |
217 (2.31) |
374 (3.94) |
539 (5.68) |
348 (3.67) |
|
40 - |
12 (0.13) |
17 (0.18) |
31 (0.33) |
31 (0.33) |
44 (0.46) |
32 (0.34) |
|
Table 3.Maternal age- and parity-specific low birth weight rate (%) in 1995 and 2005 by plurality in the Republic of Korea
Maternal age (y) |
1995
|
2005
|
Birth order
|
Birth order
|
First |
Second |
≥ Third |
First |
Second |
≥ Third |
Singleton births |
|
|
|
|
|
|
-19 |
3.77 |
4.34 |
16.67 |
5.80*
|
3.75 |
16.67 |
20 - 24 |
2.61 |
2.42 |
2.97 |
3.47*
|
2.74 |
5.11*
|
25 - 29 |
2.60 |
2.00 |
2.13 |
3.08*
|
2.34*
|
3.58*
|
30 - 34 |
3.81 |
2.59 |
2.38 |
3.77 |
2.77*
|
2.87*
|
35 - 39 |
5.46 |
4.02 |
3.35 |
5.82 |
4.08 |
4.21*
|
40 - |
5.88 |
6.32 |
4.81 |
6.82 |
5.58 |
6.32 |
Multiple births |
|
|
|
|
|
|
-19 |
56.52 |
65.00 |
- |
80.00 |
60.00 |
- |
20 - 24 |
45.86 |
38.85 |
35.57 |
48.54 |
51.94*
|
53.49*
|
25 - 29 |
41.61 |
32.95 |
38.11 |
49.65*
|
54.88*
|
38.92 |
30 - 34 |
36.91 |
33.17 |
32.67 |
49.46*
|
52.79*
|
43.83*
|
35 - 39 |
42.98 |
40.07 |
41.01 |
45.19 |
53.62*
|
45.98 |
40 - |
41.67 |
58.82 |
48.39 |
54.84 |
63.64 |
46.88 |
Table 4.Calculation process of changes in the low birth weight (LBW) rate due to changes in the distribution of age and parity (AP-dis) and changes in the age- and parity-specific LBW rate (AP-spe) among singleton and multiple births between 1995 and 2005 in the Republic of Korea
|
All live births
|
Singleton births
|
Multiple births
|
|
1995 |
2005 |
1995 |
2005 |
1995 |
2005 |
Observed absolute % points of LBW rate |
3.02 |
4.28 |
2.54a
|
3.18b
|
0.48c
|
1.10d
|
Changes in the LBW rate (% points) |
1.26 (e+f) |
0.64e (b-a) |
0.62f (d-c) |
Age-parity score (K) for 2005 |
|
|
1.126g
|
0.999h
|
Expected absolute % points of LBW rate in 2005 when there were no changes in the AP-spe |
|
|
2.86i (a×g) |
0.48j (c×h) |
Absolute % points of increase in the LBW rate due to changes in the AP-dis |
0.32 (k+l) |
0.32k (i-a) |
0.00l (j-c) |
Absolute % points of increase in the LBW rate due to changes in the AP-spe |
0.94 (m+n) |
0.32m (b-i) |
0.62n (d-j) |