Table 1 Clinical characteristics of women in the cesarean delivery group
Characteristics | Without PP history (n = 1522) | With PP history (n = 81) | P value |
|---|---|---|---|
Maternal age (years) | 32.17 ± 3.99 | 33.64 ± 3.83 | < 0.05a |
  < 35 years | 1095 (71.9%) | 48 (59.3%) |  |
  ≥ 35 years | 427 (28.1%) | 33 (40.7%) |  |
Gestational age | 38.19 ± 2.22 | 37.94 ± 2.45 | 0.553a |
  < 28 weeks | 18 (1.2%) | 2 (2.5%) |  |
 28–34 weeks | 31 (2%) | 1 (1.2%) |  |
 34–37 weeks | 78 (5.1%) | 6 (7.4%) |  |
  ≥ 37 weeks | 1394 (91.7%) | 72 (88.9%) |  |
Level of education | < 0.05 | ||
 College | 957 (62.9%) | 39 (48.1%) |  |
 Below college | 534 (35.1%) | 37 (45.6%) |  |
 Unknown | 31 (2%) | 5 (6.2%) |  |
Mode of conception | 0.837 | ||
 Natural | 1478 (97.1%) | 78 (96.3%) |  |
 ART | 44 (2.9%) | 3 (3.7%) |  |
Prior abortions | 0.533 | ||
 0 | 1012 (66.5%) | 52 (64.2%) |  |
 1 | 344 (22.6%) | 23 (28.4%) |  |
  ≥ 2 | 161 (10.6%) | 6 (7.4%) |  |
Prior deliveries | 0.632 | ||
 0 | 1442 (94.7%) | 75 (92.6%) |  |
 1 | 71 (4.7%) | 5 (6.2%) |  |
  ≥ 2 | 9 (0.6%) | 1 (1.2%) |  |
Sex of offspring | 0.824 | ||
 Male | 796 (52.3%) | 45 (55.6%) |  |
 Female | 726 (47.7%) | 36 (44.4%) |  |
Interval time | 4.08 ± 1.75 | 3.96 ± 2.01 | 0.564 |