Table 2.
Univariable analyses between the placenta accreta group and the non-placenta accreta group in the training set.
| Placenta accreta (n = 290) | Non-placenta accreta (n = 5,291) | P-value | ||
|---|---|---|---|---|
| Age | <25 | 6 (2.1) | 105 (2.0) | 0.007 |
| 25–30 | 59 (20.3) | 851 (16.1) | ||
| 30–35 | 97 (33.4) | 2,296 (43.4) | ||
| 35–40 | 101 (34.8) | 1,713 (32.4) | ||
| ≥40 | 27 (9.3) | 326 (6.2) | ||
| BMI before delivery | 27.23 ± 3.59 | 27.79 ± 3.69 | 0.032 | |
| Gravity | 1 | 1 (0.3) | 124 (2.30) | <0.001 |
| 2 | 73 (25.2) | 2,170 (41.0) | ||
| 3 | 80 (27.6) | 1,498 (28.3) | ||
| 4 | 79 (27.2) | 937 (17.7) | ||
| ≥5 | 57 (19.7) | 562 (10.6) | ||
| Parity | 0 | 2 (0.7) | 270 (5.1) | <0.001 |
| 1 | 257 (88.6) | 4,681 (88.5) | ||
| ≥2 | 31 (10.7) | 340 (6.4) | ||
| History of vaginal delivery | 9 (3.1) | 105 (2.0) | 0.190 | |
| Number of previous cesarean section | 0 | 2 (0.7) | 266 (5.0) | <0.001 |
| 1 | 264 (91) | 4,749 (89.8) | ||
| ≥2 | 24 (8.3) | 276 (5.2) | ||
| Number of previous medical abortion | 0 | 265 (91.4) | 5,037 (95.2) | 0.013 |
| 1 | 17 (5.9) | 182 (3.4) | ||
| ≥2 | 8 (2.8) | 72 (1.4) | ||
| Number of previous artificial abortion | 0 | 127 (43.8) | 3,044 (57.5) | <0.001 |
| 1 | 70 (24.1) | 1,277 (24.1) | ||
| 2 | 60 (20.7) | 681 (12.9) | ||
| ≥3 | 33 (11.4) | 289 (5.5) | ||
| History of Induction | 7 (2.4) | 141 (2.7) | 0.796 | |
| Myomectomy | 4 (1.4) | 324 (6.1) | 0.001 | |
| History of gynecological surgery | 29 (10.0) | 306 (5.8) | 0.003 | |
| Regular menstruation | 263 (90.7) | 4,874 (92.1) | 0.381 | |
| Menstrual flow | Hypomenorrhea | 24 (8.3) | 150 (2.8) | <0.001 |
| Normal | 258 (89.0) | 5,044 (95.3) | ||
| Menorrhagia | 8 (2.8) | 97 (1.8) | ||
| Dysmenorrhea | 76 (26.2) | 1,081 (20.8) | 0.018 | |
| Medications during pregnancy | 30 (10.3) | 239 (4.5) | <0.001 | |
| Pregnancy route | Conceived naturally | 288 (99.3) | 5,206 (98.4) | 0.455 |
| IVF | 2 (0.7) | 81 (1.5) | ||
| Ovarian stimulation | 0 (0.0) | 4 (0.1) | ||
| Number of previous vaginal bleeding | 0 | 147 (50.7) | 4,923 (93.0) | <0.001 |
| 1 | 77 (26.6) | 301 (5.7) | ||
| ≥2 | 66 (22.8) | 67 (1.3) | ||
| Regular perinatal visits | 232 (80.8) | 4,313 (81.5) | 0.518 | |
| Placenta previa | 252 (86.9) | 220 (4.2) | <0.001 | |
| PIH | 12 (4.1) | 858 (16.2) | <0.001 | |
| GDM | 44 (15.2) | 1,257 (15.8) | 0.001 | |
| Pregnancy complicated by medical disease | 48 (16.6) | 1,235 (23.3) | 0.007 | |
| Pregnancy complicated by surgical disease | 3 (1.0) | 93 (1.8) | 0.488 | |
| Pregnancy complicated by gynecological disease | 8 (2.8) | 462 (8.7) | <0.001 | |
| Time between last CS and pregnancy* | 91.14 ± 51.23 | 71.78 ± 44.43 | <0.001 | |
| Elected CS as last CS* | 109 (76.8) | 2,926 (81.4) | 0.166 | |
| CS during labor as last CS* | 29 (20.9) | 411 (17.9) | 0.383 |
Values are presented as the mean ± SD and number (percentage). BMI: body mass index; PIH: pregnancy-induced hypertension syndrome; GDM: gestational diabetes mellitus; CS: cesarean section; IVF: in vitro fertilization.
There were missing data in the variable. In the placenta accreta group, there were 57 (19.7%) patients with missing data in the time between last CS and pregnancy, 148 (51.0%) patients with elective CS as last CS, and 151 (52.1%) patients with CS during labor as the last CS. In the non-placenta accreta group, there were 2,406 (45.5%) with missing data in the time between last CS and pregnancy, 1,696 (32.1%) with elected CS as last CS, and 2,999 (56.7%) with CS during labor as last CS.