Table 3.
Maternal and gestation 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 | |
|---|---|---|---|---|
| Rhesus D positive (%) | 638 (95.8%) | 991 (97.9%) | 6.423 | 0.012 |
| Maternal age (years), mean ± SD | 32.63 ± 5.18 | 32.64 ± 5.14 | 0.062 | 0.951 |
| Advanced maternal age (>35 years old) | 166 (33.7%) | 248 (33.3%) | 0.015 | 0.902 |
| Maternal height (cm) | 157.66 ± 5.01 | 157.87 ± 4.91 | 0.871 | 0.384 |
| Maternal weight at delivery (kg) | 65.27 ± 9.41 | 65.05 ± 8.69 | 0.477 | 0.634 |
| Maternal BMI at delivery (kg/m2), mean ± SD | 26.25 ± 3.50 | 26.08 ± 3.27 | 0.962 | 0.336 |
| Married (%) | 633 (95.0%) | 969 (95.8%) | 0.463 | 0.549 |
| Prior miscarriages (%) | 342 (51.4%) | 496 (49.0%) | 0.879 | 0.369 |
| Prior cesarean delivery | 235 (35.3%) | 343 (33.9%) | 0.345 | 0.564 |
| Assisted reproductive techniques | 62 (9.3%) | 114 (11.3%) | 1.636 | 0.222 |
| Twins | 18 (2.7%) | 51 (5.0%) | 5.563 | 0.011 |
| Anterior placenta | 206 (45.3%) | 324 (44.7%) | 0.039 | 0.857 |
| Complete placenta previa | 266 (39.9%) | 404 (39.9%) | 0.001 | 0.999 |
| Placenta accreta spectrum | 110 (16.5%) | 155 (15.3%) | 0.435 | 0.538 |
| Predelivery hemoglobin (g/L) | 108.00 ± 18.17 | 107.49 ± 17.06 | 0.563 | 0.573 |
| Predelivery anemia (hemoglobin < 110 g/L) | 321 (51.0%) | 510 (53.0%) | 0.649 | 0.442 |
| Antepartum hemorrhage | 223 (33.5%) | 295 (29.2%) | 3.534 | 0.066 |