Table 1.
Descriptive statistics for BW in the CSHRR and the MBR by birth year groups according to MBR procedural changes
| Birth weight (grams) |
||||||
|---|---|---|---|---|---|---|
| Information source and period | N | Mean | SD | Median | Minimum | Maximum |
| CSHRR | ||||||
| 1973–1991 | 47 534 | 3342 | 564 | 3350 | 500 | 6000 |
| MBR* | ||||||
| 1973–1977 | 15 807 | 3036 | 558 | 3000 | 500 | 6000 |
| 1979–1990 | 28 708 | 3346 | 555 | 3350 | 730 | 5750 |
| 1991 | 3019 | 3391 | 564 | 3416 | 634 | 5600 |
*From 1973 to 1977, BW was recorded in 500 g units in the MBR. From 1978 to 1990, BW was recorded in 10 g units, and from 1991 onwards in 1 g units.
BW, birth weight; CSHRR, Copenhagen School Health Records Register; MBR, Medical Birth Register.