Table 1 Maternal demographics of the study cohort
Demographic data | Up to 4 VEs (n = 9716) | 5–6 VEs (n = 4624) | 7–8 VEs (n = 2999) | 9 or more VEs (n = 4844) | p-value |
|---|---|---|---|---|---|
Maternal age (years) | 30.1 (5.2) | 29.6 (5.5) | 29.2 (5.4) | 28.7 (5.4) | < 0.001 |
BMI (kg/m2) | 23.1 (3.6) | 23.3 (3.9) | 23.3 (3.9) | 23.5 (4.1) | < 0.001 |
Obesity | 508 (5.5) | 251 (5.4) | 180 (6.0) | 369 (7.6) | < 0.001 |
Gestational age (weeks) | 39.6 (1.1) | 39.6 (1.1) | 39.6 (1.1) | 39.6 (1.2) | < 0.001 |
Nulliparity | 2306 (23.7) | 1727 (31.6) | 1563 (52.1) | 3521 (72.6) | < 0.001 |
Birthweight (grams) | 3271 (407) | 3287 (418) | 3313 (422) | 3333 (599) | < 0.001 |
Small for gestational age | 389 (4.1) | 173 (3.7) | 100 (3.3) | 165 (3.4) | 0.311 |
Macrosomia | 465 (4.9) | 205 (4.4) | 169 (5.6) | 292 (6.0) | < 0.001 |
Smoking | 1046 (10.8) | 543 (11.7) | 386 (12.9) | 1052 (21.7) | < 0.001 |
TOLAC | 536 (5.5) | 227 (4.9) | 179 (5.9) | 284 (5.9) | < 0.001 |
Induction of labor | 2733 (28.1) | 1448 (31.3) | 999 (33.3) | 2117 (43.7) | < 0.001 |
Epidural | 6993 (72.0) | 3813 (82.5) | 2603 (87.8) | 4354 (89.9) | < 0.001 |
Spontaneous ROM | 1395 (14.4) | 560 (12.1) | 348 (11.6) | 503 (10.4) | < 0.001 |
Amniotomy | 8321 (85.6) | 4064 (87.9) | 2651 (88.4) | 4341 (89.6) | < 0.001 |
Normal vaginal delivery | 9377 (96.1) | 4320 (93.4) | 2729 (91.0) | 4105 (84.7) | < 0.001 |
Instrumental delivery | 211 (3.9) | 304 (6.6) | 270 (9.0) | 739 (15.3) | < 0.001 |
Diabetes mellitus | 625 (6.4) | 323 (7.0) | 237 (7.9) | 406 (8.4) | < 0.001 |
Gestational hypertensive disorders | 575 (5.9) | 250 (5.4) | 185 (6.2) | 314 (6.5) | <0.001 |
Chronic hypertension | 45 (0.4) | 16 (0.3) | 23 (0.8) | 32 (0.4) | 0.012 |
Labor duration (min) | 184 (122) | 349 (163) | 490 (204) | 682 (308) | < 0.001 |
ROM to delivery duration | 180 (179) | 250 (220) | 321 (231) | 422 (269) | < 0.001 |