Table 2 Distribution of individual potential confounding factors by birthweight
Birthweight (g) | n | Gestational age | Cesarean section | Breech presentation at birth | Maternal complicationsa | |
|---|---|---|---|---|---|---|
Mean | (SD) | (%) | (%) | (%) | ||
Overall | 205,648 | 38.5 | (2.0) | 49,964 (24.3) | 9099 (4.4) | 34,642 (16.9) |
< 1500 | 2072 | 30.6 | (4.1) | 38.9 | 18.6 | 25.3 |
1500–1599 | 602 | 33.1 | (3.2) | 32.4 | 11.1 | 20.3 |
1600–1699 | 521 | 33.7 | (3.1) | 39.3 | 12.1 | 22.5 |
1700–1799 | 811 | 34.4 | (3.0) | 35.8 | 12.1 | 20.3 |
1800–1899 | 973 | 34.6 | (2.9) | 35.9 | 10.4 | 22.1 |
1900–1999 | 1032 | 35.2 | (2.9) | 36.7 | 9.5 | 23.3 |
2000–2099 | 2807 | 36.7 | (2.6) | 26.7 | 7.5 | 15.7 |
2100–2199 | 2165 | 36.9 | (2.5) | 29.7 | 7.3 | 19.2 |
2200–2299 | 3817 | 37.2 | (2.3) | 26.2 | 6.4 | 15.6 |
2300–2399 | 4178 | 37.6 | (2.0) | 25.5 | 5.2 | 18.2 |
2400–2499 | 5628 | 37.9 | (2.0) | 25.9 | 5.5 | 18.7 |
2500–3499 | 181,042 | 38.8 | (1.6) | 23.7 | 3.9 | 16.6 |