Descriptive characteristics of pregnancies admitted for delivery between 31 + 0 and 36 + 6 weeks’ gestation, British Columbia, Canada, 2000–2013
| Characteristic | No. (%) of pregnancies* | ||
|---|---|---|---|
| Total n = 16 358 | Admission before 34 wk n = 2594 | Admission at or after 34 wk n = 13 764 | |
| Age of gestational parent, yr, mean ± SD | 31.2 ± 5.7 | 31.5 ± 5.7 | 31.1 ± 5.7 |
| Nulliparous | 8129 (49.7) | 1367 (52.7) | 6762 (49.1) |
| Pre-pregnancy BMI (kg/m2)† | 24.5 ± 5.5 | 24.5 ± 5.4 | 24.4 ± 5.5 |
| Smoking in pregnancy | 1878 (11.5) | 288 (11.1) | 1590 (11.6) |
| Neighbourhood income quintile | |||
| 1 (lowest) | 3581 (21.9) | 551 (21.7) | 3030 (22.0) |
| 2 | 3419 (20.9) | 587 (23.1) | 2832 (20.6) |
| 3 | 3235 (19.8) | 493 (19.4) | 2742 (19.9) |
| 4 | 3115 (19.0) | 466 (18.3) | 2649 (19.3) |
| 5 (highest) | 2401 (14.7) | 383 (15.1) | 2018 (14.7) |
| Missing | 607 (3.7) | 114 (4.4) | 493 (3.6) |
| Hypertensive disorder of pregnancy | 2543 (15.6) | 501 (19.3) | 2042 (14.8) |
| Diabetes in pregnancy | 2811 (17.2) | 499 (19.2) | 2312 (16.8) |
| Iatrogenic delivery‡ | 7204 (44.0) | 1151 (44.4) | 6053 (44.0) |
| Gestational age at delivery, wk | |||
| 31 | 350 (2.1) | 350 (13.5) | – |
| 32 | 629 (3.9) | 629 (24.3) | – |
| 33 | 1074 (6.6) | 1074 (41.4) | – |
| 34 | 1942 (11.9) | 357 (13.8) | 1585 (11.5) |
| 35 | 3497 (21.4) | 93 (3.6) | 3404 (24.7) |
| 36 | 7806 (47.7) | 51 (2.0) | 7755 (56.3) |
| 37 | 936 (5.7) | 24 (0.9) | 912 (6.6) |
| 38 | 79 (< 1) | 8 (0.3) | 71 (0.5) |
| ≥ 39 | 45 (< 1) | 8 (0.3) | 37 (0.3) |
| Male fetus | 9243 (56.5) | 1522 (58.7) | 7721 (56.1) |
| Birthweight, g, mean ± SD | 2671 ± 534 | 2110 ± 486 | 2777 ± 473 |