Table 2 Characteristics of study populations
Variable | All (n = 112138) n (%) | Tertiary hospital (n = 79631) n (%) | Secondary hospital (n = 32507) n (%) | X 2 | p |
|---|---|---|---|---|---|
Maternal age (years) | <0.001 | ||||
(Years) | 29 (26–31) | 26 (23–30) | |||
≤ 24 | 25734 (23.1) | 12950 (16.4) | 12784 (39.7) | ||
25–34 | 74355 (66.8) | 57536 (72.8) | 16819 (52.2) | ||
≥ 35 | 11197 (10.1) | 8583 (10.9) | 2614 (8.1) | ||
Maternal education level | <0.001 | ||||
College or above | 55473 (51.3) | 46093 (59.0) | 9380 (31.3) | ||
High school | 29935 (27.7) | 20411 (26.1) | 9524 (31.8) | ||
Primary school | 22468 (20.8) | 11442 (14.6) | 11026 (36.8) | ||
Illiteracy | 258 (0.2) | 214 (0.3) | 44 (0.1) | ||
Residents | 77661 (69.3) | 56595 (71.1) | 21066 (64.8) | 425.80 | <0.001 |
Obesity | 15980 (17.4) | 12512 (19.0) | 3468 (13.2) | 1584.92 | <0.001 |
Primiparous | 90971 (81.1) | 66827 (83.9) | 24144 (74.3) | 1403.10 | <0.001 |
Previous bad obstetric history | 1084 (1.0) | 952 (1.2) | 132 (0.4) | 150.28 | <0.001 |
Male infants | 61345 (54.7) | 43028 (54.3) | 18137 (55.8) | 28.84 | <0.001 |
Multiple fetus | 1918 (1.7) | 1771 (2.2) | 147 (0.5) | 431.05 | <0.001 |
GDM/DM | 5344 (4.8) | 5024 (6.3) | 320 (1.0) | 1442.08 | <0.001 |
HDCP | 5357 (4.8) | 4594 (5.8) | 763 (2.3) | 594.21 | <0.001 |
Preeclampsia/eclampsia | 4137 (3.7) | 3650 (4.6) | 487 (1.5) | 618.52 | <0.001 |
PROM | 17078 (15.2) | 13965 (17.5) | 3113 (9.6) | 1133.14 | <0.001 |
Preterm birth | 9014 (8.0) | 8156 (10.2) | 858 (2.6) | 1805.02 | <0.001 |
Late pregnancy bleeding | 2364 (2.1) | 2127 (2.7) | 237 (0.7) | 421.85 | <0.001 |
oligohydrammios | 4200 (3.7) | 2938 (3.7) | 1262 (1.6) | 2.37 | 0.12 |
Fetus weight ≥ 4000 g | 7366 (6.7) | 5075 (6.5) | 2291 (7.1) | 14.38 | <0.001 |