Characteristics of the study population
| Characteristic | No. (%)* of mothers n = 52 438 | Standardized differences (95% CI) | |
|---|---|---|---|
| First child taken into care before conception of second child n = 1284 | First child not taken into care before birth of second child n = 51 154 | ||
| During pregnancy of first child | |||
| Diagnosis of substance use disorder | 119 (9.3) | 588 (1.2) | 0.37 (0.31 to 0.42) |
| Prenatal care (R-GINDEX) | |||
| Intensive | 60 (4.7) | 2359 (4.6) | 0 (−0.05 to 0.06) |
| Adequate | 250 (19.5) | 19 507 (38.1) | −0.42 (−0.48 to −0.36) |
| Intermediate | 455 (35.4) | 17 960 (35.1) | 0.01 (−0.05 to 0.06) |
| Inadequate | 452 (35.2) | 9749 (19.1) | 0.37 (0.31 to 0.42) |
| No care | 67 (5.2) | 1579 (3.09) | 0.11 (0.05 to 0.16) |
| At birth of first child | |||
| Year | |||
| 1998–2003 | 461 (35.9) | 17 316 (33.9) | 0.04 (−0.01 to 0.1) |
| 2004–2009 | 550 (42.8) | 21 533 (42.1) | 0.01 (−0.04 to 0.07) |
| 2010–2015 | 273 (21.3) | 12 305 (24.1) | −0.07 (−0.12 to −0.01) |
| Mother’s age, mean ± SD; yr | 19.1 ± 3.5 | 25.7 ± 5.4 | −0.09 (−0.15 to −0.04) |
| Urban neighbourhood | 828 (64.5) | 29 828 (58.3) | 0.13 (0.07 to 0.18) |
| Income quintile of neighbourhood | |||
| 1 (Lowest income) | 714 (55.6) | 11 864 (23.2) | 0.7 (0.65 to 0.76) |
| 2 | 246 (19.2) | 10 894 (21.3) | −0.05 (−0.11 to 0.00) |
| 3 | 147 (11.5) | 10 069 (19.7) | −0.23 (−0.28 to −0.17) |
| 4 | 77 (6.0) | 9867 (19.3) | −0.41 (−0.46 to −0.35) |
| 5 (Highest income) | 62 (4.8) | 8317 (16.3) | −0.38 (−0.44 to −0.33) |
| Missing data | 38 (3.0) | 143 (0.3) | 0.21 (0.16 to 0.27) |
| Between birth of first child and conception of second child | |||
| Time period, mean ± SD; yr | 2.9 ± 2.4 | 2.2 ± 1.8 | 0.04 (−0.01 to 0.10) |
| Moved | 827 (64.4) | 18 386 (35.9) | 0.59 (0.54 to 0.65) |
| Received income assistance | 883 (68.8) | 6879 (13.5) | 1.36 (1.30 to 1.41) |
| Diagnosis of diabetes | 50 (3.9) | 831 (1.6) | 0.14 (0.09 to 0.20) |
| Diagnosis of hypertension | 41 (3.2) | 1890 (3.7) | −0.03 (−0.08 to 0.03) |
| Diaganosis of substance use disorder | 320 (24.9) | 1425 (2.8) | 0.68 (0.62 to 0.73) |
Note: CI = confidence interval, R-GINDEX = Revised Graduated Prenatal Care Utilization Index, SD = standard deviation.
↵* Unless specified otherwise.