Table 2.
Crude and multivariable associations of economic and educational position with maternal outcomes among the ALSPAC and Pelotas birth cohort studies
| Models | Relative index of inequality: OR for each outcome comparing those at the bottom to those at the top of the income or educational hierarchy (95% CI) | |||||||
| Income | Education | |||||||
| ALSPAC 1991/92 | Pelotas 1982 | Pelotas 1993 | Pelotas 2004 | ALSPAC 1991/92 | Pelotas 1982 | Pelotas 1993 | Pelotas 2004 | |
| Ever smoked during pregnancy | ||||||||
| Crude | 12.4 (10.0 to 15.3) | 2.5 (2.1 to 3.0) | 2.3 (1.9 to 2.9) | 4.9 (3.8 to 6.3) | 7.4 (6.2 to 8.7) | 1.7 (1.4 to 2.1) | 3.5 (2.8 to 4.4) | 7.8 (5.9 to 10.2) |
| Model 1 | 12.6 (10.0 to 15.7) | 2.6 (2.1 to 3.2) | 2.3 (1.8 to 2.8) | 4.9 (3.8 to 6.4) | 7.8 (6.5 to 9.4) | 1.8 (1.4 to 2.2) | 3.8 (3.1 to 4.8) | 8.0 (5.9 to 10.7) |
| Model 2 | 9.5 (7.5 to 12.0) | 2.3 (1.8 to 2.9) | 2.0 (1.6 to 2.5) | 3.6 (2.7 to 4.7) | 6.3 (5.2 to 7.7) | 1.6 (1.3 to 2.0) | 3.2 (2.5 to 4.1) | 5.2 (3.8 to 7.2) |
| Model 2+other SEP score | 5.9 (4.6 to 7.7) | 2.4 (1.8 to 3.3) | 1.4 (1.1 to 1.8) | 2.3 (1.7 to 3.1) | 3.8 (3.0 to 4.9) | 0.9 (0.7 to 1.3) | 2.8 (2.1 to 3.6) | 3.8 (2.7 to 5.3) |
| Caesarean section | ||||||||
| Crude | 0.6 (0.5 to 0.8) | 0.2 (0.1 to 0.3) | 0.3 (0.2 to 0.3) | 0.3 (0.2 to 0.3) | 0.8 (0.7 to 1.1) | 0.2 (0.2 to 0.3) | 0.2 (0.2 to 0.3) | 0.2 (0.1 to 0.2) |
| Model 1 | 0.6 (0.4 to 0.7) | 0.2 (0.1 to 0.3) | 0.3 (0.2 to 0.3) | 0.3 (0.2 to 0.4) | 0.8 (0.6 to 1.0) | 0.2 (0.2 to 0.3) | 0.2 (0.2 to 0.3) | 0.2 (0.1 to 0.2) |
| Model 2 | 0.6 (0.5 to 0.9) | 0.2 (0.2 to 0.3) | 0.3 (0.2 to 0.4) | 0.4 (0.3 to 0.5) | 0.9 (0.7 to 1.2) | 0.3 (0.2 to 0.3) | 0.3 (0.2 to 0.3) | 0.2 (0.2 to 0.3) |
| Model 3 | 0.6 (0.4 to 0.8) | – | 0.3 (0.2 to 0.4) | 0.4 (0.3 to 0.5) | 0.8 (0.6 to 1.1) | – | 0.2 (0.2 to 0.3) | 0.3 (0.2 to 0.3) |
| Model 4 | 0.6 (0.4 to 0.8) | 0.2 (0.2 to 0.3) | 0.3 (0.2 to 0.4) | 0.4 (0.3 to 0.5) | 0.8 (0.6 to 1.1) | 0.3 (0.2 to 0.3) | 0.3 (0.2 to 0.3) | 0.2 (0.2 to 0.3) |
| Model 4+other SEP score | 0.6 (0.4 to 0.9) | 0.4 (0.3 to 0.6) | 0.4 (0.3 to 0.6) | 0.6 (0.4 to 0.7) | 0.9 (0.7 to 1.4) | 0.5 (0.3 to 0.6) | 0.4 (0.3 to 0.5) | 0.3 (0.2 to 0.4) |
| Delivery not assisted by doctor | ||||||||
| Crude | 1.8 (1.5 to 2.3) | 6.6 (5.4 to 8.0) | 3.0 (2.2 to 4.0) | 3.2 (2.2 to 4.6) | 2.5 (2.1 to 3.0) | 5.4 (4.4 to 6.6) | 3.2 (2.3 to 4.4) | 2.5 (1.7 to 3.6) |
| Model 1 | 2.0 (1.6 to 2.5) | 6.7 (5.4 to 8.3) | 2.9 (2.1 to 4.0) | 2.8 (1.9 to 4.1) | 2.6 (2.1 to 3.1) | 5.5 (4.3 to 6.8) | 3.2 (2.3 to 4.4) | 2.4 (1.6 to 3.6) |
| Model 2 | 1.9 (1.5 to 2.4) | 6.1 (4.8 to 7.8) | 2.6 (1.8 to 3.5) | 2.2 (1.5 to 3.3) | 1.9 (1.5 to 2.3) | 4.3 (3.4 to 5.5) | 2.6 (1.8 to 3.6) | 1.6 (1.0 to 2.5) |
| Model 3 | 1.9 (1.5 to 2.5) | – | 2.6 (1.9 to 3.6) | 2.4 (1.6 to 3.5) | 2.0 (1.6 to 2.6) | – | 2.7 (1.9 to 3.9) | 1.7 (1.1 to 2.7) |
| Model 4 | 1.8 (1.4 to 2.3) | 5.9 (4.7 to 7.6) | 2.5 (1.8 to 3.5) | 2.2 (1.5 to 3.3) | 1.9 (1.5 to 2.4) | 4.3 (3.4 to 5.4) | 2.6 (1.8 to 3.8) | 1.5 (1.0 to 2.4) |
| Model 5 | 1.6 (1.2 to 2.1) | 4.6 (3.5 to 6.1) | 1.9 (1.3 to 2.7) | 1.6 (1.0 to 2.5) | 2.0 (1.5 to 2.6) | 3.0 (2.3 to 4.0) | 1.9 (1.3 to 2.7) | 0.9 (0.6 to 1.4) |
| Model 5+other SEP score | 1.3 (1.0 to 1.8) | 3.8 (2.7 to 5.3) | 1.7 (1.1 to 2.4) | 1.8 (1.1 to 2.8) | 1.8 (1.3 to 2.5) | 1.4 (1.0 to 2.0) | 1.6 (1.1 to 2.3) | 0.7 (0.4 to 1.2) |
Model 1: adjusted for pre-pregnancy body mass index.
Model 2: Model 1+ethnic origin, maternal age, marital status and parity.
Model 3: Model 2+urinary infection, hypertension, hospital admission during pregnancy.
Model 4: Model 3+ever smoked during pregnancy for the ALSPAC and Pelotas 1993 and 2004; Model 2 + ever smoked during pregnancy for the Pelotas 1982 cohort study.
Model 5: Model 4+caesarean section.