Table 1.
Summary Statistics.
| Variable | Shanghai locals (n =68 367) | Migrants (n = 36 314) | All (N =104 681) | |||
|---|---|---|---|---|---|---|
| Binary variable | No. | % | No. | % | No. | % |
| Adverse birth outcomes | 15 816 | 23.1 | 8990 | 24.8 | 24 806 | 23.7 |
| Fetal diseases | 2505 | 3.7 | 1187 | 3.3 | 3692 | 3.5 |
| Congenital malformation | 523 | 0.8 | 254 | 0.7 | 777 | 0.7 |
| Neonatal disease | 12 185 | 17.8 | 7366 | 20.3 | 19 551 | 18.7 |
| Other infant health condition | 602 | 0.9 | 183 | 0.5 | 785 | 0.7 |
| Ethnicity (not Han) | 556 | 0.8 | 845 | 2.3 | 1401 | 1.3 |
| Nationality (not Chinese) | 101 | 0.1 | 185 | 0.5 | 286 | 0.3 |
| Occupation (employed) | 65 924 | 96.4 | 32 202 | 88.7 | 98 126 | 93.7 |
| High-risk pregnancy | 33 952 | 49.7 | 19 405 | 53.4 | 53 357 | 51.0 |
| Maternal near-miss | 70 | 0.1 | 63 | 0.2 | 133 | 0.1 |
| Cesarean delivery | 28 718 | 14.2 | 13 381 | 12.5 | 42 099 | 40.2 |
| Complications of pregnancy | 9725 | 42 | 4536 | 36.8 | 14 261 | 13.6 |
| Gestational diabetes mellitus | 7345 | 10.7 | 3193 | 8.8 | 10 538 | 10.1 |
| Continuous variable | Mean | SD | Mean | SD | Mean | SD |
| Age | 30.87 | 3.924 | 30.08 | 4.045 | 30.6 | 3.984 |
| Gestation weeks | 39.05 | 2.494 | 39.07 | 4.456 | 39.06 | 3.309 |
| Gravida | 1.705 | 0.992 | 1.934 | 1.172 | 1.784 | 1.064 |
| Birth parity | 1.211 | 0.416 | 1.274 | 0.487 | 1.233 | 0.443 |
| Rescue times | 0.00294 | 0.0552 | 0.00432 | 0.066 | 0.00342 | 0.0592 |
Note. Binary variables are presented as number and percentage (%). Continuous variables including age, gestation weeks, gravida, birth parity, and rescue times are presented as mean and SD.