Table 2 Comparison of maternal characteristics between ALSPAC (n = 13 798) and 2004 Pelotas (n = 4109) birth cohort studies.
| Variable |
ALSPAC n(%) |
Pelotas n(%) | P* |
|---|---|---|---|
| Ethnic origin | <0.001 | ||
| White | 11855 (97.4) | 3014 (73.4) | |
| Black/mixed | 318 (2.6) | 1095 (26.6) | |
| Maternal age (y) | <0.001 | ||
| <20 | 649 (4.7) | 773 (18.8) | |
| 20–34 | 11780 (85.4) | 2785 (67.8) | |
| ≥ 35 | 1369 (9.9) | 549 (13.4) | |
| Marital status | <0.001 | ||
| With partner | 11442 (97.5) | 3451 (84.0) | |
| Single mother | 288 (2.5) | 658 (16.0) | |
| Parity | <0.001 | ||
| 0 | 5672 (45.1) | 1624 (39.6) | |
| 1 | 4388 (34.8) | 1082 (26.3) | |
| ≥ 2 | 2526 (20.1) | 1402 (34.1) | |
| Pre-pregnancy body mass index (kg/m 2 ) | <0.001 | ||
| <18.5 | 570 (5.0) | 187 (4.9) | |
| 18.5 – 24.9 | 8472 (74.4) | 2333 (61.3) | |
| 25.0 – 29.9 | 1718 (15.1) | 873 (23.0) | |
| ≥ 30 | 627 (5.5) | 409 (10.8) | |
| Antenatal risk | <0.001 | ||
| Low | 2678 (49.7) | 717 (18.1) | |
| Medium | 2268 (42.2) | 2702 (68.0) | |
| High | 435 (8.1) | 551 (13.9) | |
| Smoking during pregnancy | 0.565 | ||
| No | 8179 (75.9) | 3099 (75.4) | |
| Yes | 2601 (24.1) | 1010 (24.6) | |
| Multiple birth | 0.110 | ||
| No | 13617 (98.7) | 4068 (99.0) | |
| Yes | 181 (1.3) | 41 (1.0) | |
| Neonatal problems | 0.001 | ||
| No | 11261 (93.3) | 3755 (91.7) | |
| Yes | 813 (6.7) | 342 (8.4) |