Table 4.
Labor characteristics of the participant pregnant women by type O vs. non-type O blood groups.
| Type O (n = 666, 39.7%) | Non-type O (n = 1012, 60.3%) | t/Z/χ2 value | p value | |
|---|---|---|---|---|
| Gestational age at delivery (week), mean ± SD | 37.16 ± 2.47 | 36.97 ± 2.57 | 1.496 | 0.135 |
| Preterm birth (<37 week) | 270 (41.3%) | 421 (42.4%) | 0.193 | 0.683 |
| Emergency admission | 595 (89.3%) | 894 (88.3%) | 0.401 | 0.529 |
| Cesarean delivery | 510 (76.6%) | 765 (75.6%) | 0.213 | 0.683 |
| Estimated blood loss (mL), median (IQR) | 600 (400-1300) | 500 (350-1100) | 1.225 | 0.221 |
| Postpartum hemorrhage | 165 (24.8%) | 226 (22.3%) | 1.341 | 0.262 |
| Cesarean hysterectomy | 7 (1.1%) | 12 (1.2%) | 0.065 | 0.820 |
| Transfusion of blood products | 230 (34.5%) | 323 (31.9%) | 1.246 | 0.266 |
| Postdelivery hemoglobin (g/L) | 102.78 ± 15.42 | 101.58 ± 15.58 | 1.421 | 0.155 |
| Postdelivery anemia (hemoglobin < 110 g/L) | 390 (70.3%) | 594 (70.5%) | 0.012 | 0.952 |
| Placental length (cm) | 19.20 ± 2.20 | 19.22 ± 2.43 | 0.155 | 0.876 |
| Placental width (cm) | 18.65 ± 2.05 | 18.72 ± 2.32 | 0.587 | 0.557 |
| Placental depth (cm) | 2.21 ± 0.42 | 2.22 ± 0.42 | 0.538 | 0.591 |
| Placental surface area (cm2) | 283.65 ± 62.93 | 287.46 ± 97.51 | 1.083 | 0.279 |
| Placental volume (cm3) | 436.62 ± 306.50 | 452.34 ± 370.97 | 0.901 | 0.368 |
| Placental weight (g) | 580.71 ± 178.59 | 583.31 ± 169.09 | 0.250 | 0.803 |
| Male newborn | 378 (56.8%) | 597 (59.0%) | 0.824 | 0.390 |
| Neonatal asphyxia | 61 (9.2%) | 60 (5.9%) | 6.264 | 0.016 |
| Admission to the neonatal intensive care unit | 161 (24.2%) | 213 (21.0%) | 2.267 | 0.134 |
| Apgar score of <7 at 1 min | 53 (8.0%) | 58 (5.7%) | 3.224 | 0.087 |
| Apgar score of <7 at 5 min | 5 (0.8%) | 9 (0.9%) | 0.093 | 0.794 |
| Apgar score of <7 at 10 min | 1 (0.2%) | 4 (0.4%) | 0.812 | 0.654 |