Table 1 Baseline characteristics and pregnancy outcomes of women with imminent preterm birth at participating Canadian Perinatal Network sites (2005–15) (N (%) women or median [IQR], unless otherwise stated)
Total N = 7888 | Pre-MAG-CP (2005–2011) N = 4745 | MAG-CP (2011–2015) N = 3143 | p values | |
|---|---|---|---|---|
Maternal demographics and past history | ||||
Maternal age at EDD (year) | 31 [27, 35] | 31 [27,35] | 31 [27,35] | 0.034 |
Pre-existing medical conditions | ||||
Pre-existing hypertension | 305 (3.9%) | 178 (3.8%) | 127 (4.0%) | 0.600 |
Diabetes mellitus | 149 (1.9%) | 79 (1.7%) | 70 (2.2%) | 0.090 |
Venous thromboembolism | 28 (0.4%) | 25 (0.5%) | 3 (0.1%) | 0.001 |
Prior obstetric history | ||||
Previous preterm birth | 1383 (17.5%) | 845 (17.8%) | 538 (17.1%) | 0.400 |
Previous caesarean | 930 (11.8%) | 666 (14.0%) | 264 (8.4%) | < 0.001 |
Current pregnancy | ||||
Nulliparity | 3909 (49.6%) | 2303 (48.5%) | 1606 (51.1%) | 0.030 |
Multiple gestation | 1507 (19.1%) | 911 (19.2%) | 596 (19.0%) | 0.800 |
Smoking during pregnancy | 1260 (16.0%) | 833 (17.6%) | 427 (13.6%) | < 0.001 |
Missing | 52 | 33 | 19 | |
Gestational age at enrollment (week) | 26.0 [24.4, 27.4] | 26.1 [24.6, 27.6] | 25.9 [24.4, 27.4] | < 0.001 |
Indication for threatened preterm birth | ||||
Preterm labour only | 2324 (29.5%) | 1375 (29.0%) | 949 (30.2%) | < 0.001 |
PPROM only | 1567 (19.9%) | 960 (20.2%) | 607 (19.9%) | |
PTL and PPROM | 1106 (14.0%) | 591 (12.5%) | 515 (16.4%) | |
Antepartum haemorrhage only | 1195 (15.1%) | 764 (16.1%) | 431 (13.7%) | |
Other† | 1696 (21.5%) | 1055 (22.2%) | 641 (20.4%) | |
Gestational age at delivery (week) | 28.0 [26.0, 35.0] | 28.0 [26.0, 35.0] | 28.0 [26.0, 34.0] | 0.036 |
≥ 37 weeks (and 0 days) | 1404 (17.8%) | 889 (18.7%) | 515 (16.4%) | 0.008 |
34 weeks (and 0 days)–36 weeks (and 6 days) | 821 (10.4%) | 507 (10.7%) | 314 (10.0%) | |
29 weeks (and 0 days)–33 weeks (and 6 days) | 1522 (19.3%) | 926 (19.5%) | 596 (19.0%) | |
< 29 weeks (and 0 days) | 4141 (52.5%) | 2423 (51.1%) | 1718 (54.7%) | |
Maternal outcomes | ||||
Placental abruption after enrollment | 635 (8.1%) | 251 (5.3%) | 384 (12.2%) | < 0.001 |
One/more serious maternal complications | 2479 (31.4%) | 1304 (27.5%) | 1175 (37.4%) | < 0.001 |
Death | 2 (0.03%) | 2 (0.04%) | 0 | 0.500 |
Admission to ICU or HDU | 98 (1.2%) | 19 (0.4%) | 79 (2.5%) | < 0.001 |
Chorioamnionitis | 1789 (22.7%) | 999 (21.1%) | 790 (25.1%) | < 0.001 |
Cardiovascular | 2 (0.03%) | 1 (0.02%) | 1 (0.03%) | 0.999 |
Respiratory | 64 (0.8%) | 38 (0.8%) | 26 (0.8%) | 0.999 |
CNS | 7 (0.09%) | 5 (0.1%) | 2 (0.06%) | 0.700 |
Renal | 6 (0.08%) | 4 (0.08%) | 2 (0.06%) | 0.999 |
Hematological | 72 (0.9%) | 37 (0.8%) | 17 (0.5%) | 0.300 |
Hepatic | 11 (0.1%) | 11 (0.2%) | 0 | 0.004 |
Infection | 74 (0.9%) | 50 (1.1%) | 24 (0.8%) | 0.200 |
Perinatal outcomes | N = 9541 | N = 5751 | N = 3790 | |
Stillbirth | 291 (3.0%) | 211 (3.7%) | 80 (2.1%) | < 0.001 |
Neonatal death in the delivery room | 164 (1.7%) | 119 (2.1%) | 45 (1.2%) | 0.002 |
Liveborn and admitted to NICU | 7638 (80.1%) | 4714 (82.0%) | 2924 (77.2%) | <0.001 |