Table 1 Demographic and reproductive information in the total population and according to labor type
Total population (n = 512) | Induction of labor (n = 148) | Spontaneous labor (n = 364) | Comparison between labor groups | |
Female age: Mean (range, SD) | 30.3 (19.0–43.5, 5.0) | 31.45 (19.7–43.6,4.9) | 29.8 (19.0–42.0, 5.0) | p = 0.001 |
Prior live births: Mean (range, SD) | 1.0 (0–3, 0.5) | 0.99 (0–3, 0.7) | 0.99 (0–3, 0.4) | p = 0.93 |
Gravida: Mean (range, SD) | 2.6 (2–11, 1.2) | 3.1 (2–8, 1.5) | 2.4 (2–11, 1.0) | p < 0.001 |
Multiple gestation: n (%) | 2 (0.4) | 1 (0.7) | 1 (0.3) | p = 0.51 |
Gestational age at delivery: Mean (range, SD) | 37.9 (20.0–44.3, 2.6) | 38.8 (34.7–42.4, 1.5) | 37.5 (20.0–44.3, 2.8) | p < 0.001 |
Recent or current smokera: n (%) | 46 (10.3) | 21 (15.4) | 25 (7.1) | p = 0.005 |
BMI: Mean (range, SD) | 25.3 (17.2–65.2, 4.6) | 26.3 (18.0–65.2, 5.5) | 25.0 (17.2–47.6, 4.1) | p = 0.03 |
Prior VTE: n (%) | 2 (0.4) | 1 (0.7) | 1 (0.3) | p = 0.503 |
Race: n (%) | ||||
Caucasian | 447 (87.3) | 121 (81.8) | 326 (89.6) | p = 0.016 |
Asian | 16 (3.1) | 8 (5.4) | 8 (2.2) | p = 0.059 |
Black | 17 (3.3) | 4 (2.7) | 13 (3.6) | p = 0.619 |
Other | 14 (2.7) | 7 (4.7) | 7 (1.9) | p = 0.078 |
Unknown | 18 (3.5) | 8 (5.4) | 10 (2.7) | – |
Placenta-mediated pregnancy complications in a previous pregnancy | ||||
Pre-term delivery < 37 wks: n (%) | 420 (82.4) | 106 (72.1) | 314 (86.5) | p < 0.001 |
Pre-eclampsia: n (%) | 314 (61.3) | 80 (54.1) | 234 (64.3) | p = 0.031 |
Placental abruption: n (%) | 151 (29.5) | 18 (12.2) | 133 (36.5) | p < 0.001 |
SGA < 10th percentile: n (%) | 143 (28.0) | 44 (29.7) | 99 (27.3) | p = 0.587 |
Prior pregnancy loss: n (%) | 146 (28.5) | 74 (50.0) | 72 (19.8) | p < 0.001 |
Mean prior pregnancy losses (range, SD) | 0.57 (0–9, SD 1.2) | 1.08 (0–6, SD 1.4) | 0.36 (0–9, SD 1.0) | p < 0.001 |
Prior late loss > 20 weeks: n (%) | 68 (14.2%) | 36 (28.6%) | 32 (9.0%) | p < 0.001 |
Placenta-mediated pregnancy complications during the AFFIRM study pregnancy | ||||
Pre-term delivery < 37 weeks: n (%) | 141 (27.5) | 10 (6.8) | 131 (36.0) | p < 0.001 |
Pre-eclampsia: n (%) | 31 (6.1) | 15 (10.1) | 16 (4.4) | p = 0.014 |
Placental abruption: n (%) | 2 (0.40) | 0 (0) | 2 (0.5) | p = 0.366 |
SGA < 10th percentile: n (%) | 74 (14.5) | 23 (15.5) | 51 (14.0) | p = 0.742 |
LMWH use during pregnancy: n (%) | 274 (53.5) | 82 (55.4) | 192 (52.7) | p = 0.585 |