Table 1 Basic characteristics of the participants according to the presence or absence of placenta accreta spectrum
From: Risk factors for placenta accreta spectrum: findings from the Japan environment and Children’s study
Variable | PAS (+) N = 202 | PAS (−) N = 90,352 | P value |
|---|---|---|---|
Maternal age, mean years (SD) | 32.4 (5.3) | 31.2 (5.0) | < 0.001a |
Maternal age category, % (n) | |||
≤ 19 years | 1.0 (2) | 0.8 (743) | 0.001b |
20–24 years | 6.4 (13) | 9.1 (8192) | |
25–29 years | 21.8 (44) | 27.7 (25011) | |
30–34 years | 32.2 (65) | 35.4 (32025) | |
35–39 years | 29.7 (60) | 22.4 (20274) | |
≥ 40 years | 8.9 (18) | 4.5 (4107) | |
Primiparous, % (n) | 37.6 (76) | 40.6 (36643) | 0.397b |
ART pregnancy, % (n) | 19.3 (39) | 2.9 (2619) | < 0.001b |
Maternal smoking status, % (n) | |||
Never smoker | 81.7 (165) | 82.2 (74294) | 0.029b |
Quit smoking during early pregnancy | 9.9 (20) | 13.0 (11742) | |
Smoking during pregnancy | 8.4 (17) | 4.8 (4316) | |
Number of IAs, % (n) | |||
0 | 81.2 (164) | 84.2 (76073) | 0.468b |
1 | 13.4 (27) | 11.6 (10506) | |
≥ 2 | 5.4 (11) | 4.2 (3773) | |
BMI, kg/m2, % (n) | |||
< 18.5 | 16.2 (32) | 16.2 (14471) | 0.925b |
18.5–24.9 | 72.2 (143) | 73.1 (65362) | |
≥ 25 | 11.6 (23) | 10.8 (9618) | |
Endometriosis, % (n) | 5.9 (12) | 3.7 (3301) | 0.084b |
Uterine myoma, % (n) | 8.9 (18) | 6.1 (5475) | 0.090b |
Adenomyosis, % (n) | 1.0 (2) | 0.3 (295) | 0.099c |
Uterine anomaly, % (n) | 1.5 (3) | 0.3 (256) | 0.021c |
Gestational age, mean weeks (SD) | 38.7 (2.1) | 38.7 (2.1) | 0.964a |
Placenta previa, % (n) | 8.9 (18) | 0.6 (513) | < 0.001b |
Cesarean section, % (n) | 16.8 (34) | 19.3 (17301) | 0.378b |
Maternal blood transfusion, % (n) | 19.3 (39) | 0.4 (416) | < 0.001b |