Table 1. Demographics and Other Characteristics of the Populationa.
| Characteristic | Total | Parity group | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Nulliparas | Prior cesarean | No prior cesareanb | |||||||
| Mode of delivery | Mode of delivery | Mode of delivery | Mode of delivery | ||||||
| Cesarean | Vaginal | Cesarean | Vaginal | Cesarean | Vaginal | Cesarean | Vaginal | ||
| Total n(%) | 17,434 (14.0) | 106,955 (86.0) | 12,500 (21.8) | 44,730 (78.2) | 1,977 (37.4) | 3,311 (62.4) | 2,957 (4.8) | 58,914 (95.2) | |
| Maternal age (years)c | <35 | 14,596 (83.7) | 93,673 (87.6) | 10,884 (87.1) | 41,791 (93.4) | 1,574 (79.6) | 2,607 (78.7) | 2,138 (72.3) | 49,275 (83.6) |
| ≥35 | 2,829 (16.2) | 13,188 (12.3) | 1,612 (12.9) | 2,896 (6.5) | 402 (20.3) | 700 (21.1) | 815 (27.6) | 9,592 (16.3) | |
| Mean (SD) | 27.6 (6.5) | 27.1 (6.0) | 26.5 (6.4) | 24.6 (5.8) | 29.4 (5. 8) | 29.8 (5.5) | 30.6 (6.0) | 28.8 (5.4) | |
| Maternal height (meters) | <1.5 | 747 (4.3) | 2,215 (2.1) | 519 (4.2) | 862 (1.9) | 106 (5.4) | 101 (3.1) | 122 (4.1) | 1252 (2.1) |
| ≥1.5 | 16,687 (95.7) | 104,740 (97.9) | 11,981 (95.8) | 43,868 (98.1) | 1,871 (94.6) | 3,210 (96.9) | 2,835 (95.9) | 57,662 (97.9) | |
| Mean (SD) | 1.62 (0.07) | 1.64 (0.07) | 1.62 (0.07) | 1.64 (0.07) | 1.62 (0.08) | 1.63 (0.07) | 1.62 (0.07) | 1.64 (0.07) | |
| Maternal Race | Black | 4,457 (25.6) | 20,931 (19.6) | 2,969 (23.8) | 8,651 (19.3) | 503 (25.4) | 746 (22.5) | 985 (22.5) | 11,534 (19.6) |
| Hispanic | 3,557 (20.4) | 19,102 (17.9) | 2,386 (19.1) | 7,525 (16.8) | 473 (23.9) | 614 (18.5) | 698 (23.6) | 10,963 (18.6) | |
| White | 7,443 (42.7) | 56,784 (53.1) | 5,669 (45.4) | 23,524 (52.6) | 771 (39.0) | 1,655 (50.0) | 1003 (33.9) | 31,605 (53.6) | |
| Other | 1977 (11.3) | 10,138 (9.5) | 1,476 (11.8) | 5,030 (11.8) | 230 (11.6) | 296 (8.9) | 271 (9.2) | 4,812 (8.2) | |
| Parity | Nulliparas | 12,500 (71.7) | 44,730 (41.8) | 12,500 (100.0) | 44,730 (100.0) | 0 | 0 | 0 | 0 |
| Multiparas | 4,934 (28.3) | 62,225 (58.2) | 0 | 0 | 1,977 (100.0) | 3,311 (100.0) | 2,957 (100.0) | 58,914 (100.0) | |
| BMI Category (kg/m2) | <25.0 | 1,327 (7.6) | 16,903 (15.8) | 1,011(8.1) | 8,102 (18.1) | 130 (6.6) | 393 (11.9) | 186 (6.3) | 8,408 (14.3) |
| 25.0-29.9 | 5,579 (32.0) | 44,005 (41.1) | 4,172 (33.4) | 19,381 (43.3) | 616 (31.2) | 1,275 (38.5) | 791 (26.8) | 23,349 (39.6) | |
| 30.0-34.9 | 5,157 (29.6) | 28,084 (26.3) | 3,676 (29.4) | 10,998 (24.6) | 583 (29.5) | 920 (27.8) | 898 (30.4) | 16,166 (27.4) | |
| 35.0-39.9 | 2,941 (16.9) | 11,496 (10.7) | 1,994 (16.0) | 4,051 (9.1) | 363(18.4) | 468 (14.1) | 584 (19.7) | 6,977 (11.8) | |
| >40.0 | 2430 (13.9) | 6,467 (6.0) | 1,647 (13.2) | 2,198 (4.9) | 285 (14.4) | 255 (7.7) | 498 (16.8) | 4,014 (6.8) | |
| Mean (SD) | 32.9 (6.9) | 30.2 (5.7) | 32.6 (6.8) | 29.6 (5.4) | 33.2 (6.9) | 31.1 (5.9) | 33.8 (7.0) | 30.5 (5.8) | |
| Gestational age (weeks) | Mean (SD) | 39.5 (1.2) | 39.2 (1.1) | 39.6 (1.2) | 39.4 (1.1) | 39.0 (1.2) | 39.2 (1.1) | 39.3 (1.2) | 39.1 (1.1) |
| Dilation at admission (cm)d | Mean (SD) | 2.2 (1.7) | 3.5 (2.2) | 2.0 (1. 7) | 3.1 (2.1) | 2.3 (1.8) | 3.9 (2.3) | 2.7 (1.8) | 3.8 (2.1) |
| Prior Cesarean | 1,977 (11.3) | 3,311 (3.1) | 0 | 0 | 1,977 (100.0) | 3,311 (100.0) | 0 | 0 | |
| Diabetes | 1,102 (6.3) | 3,988 (3.7) | 718 (5.7) | 1,288 (2.9) | 116 (5.9) | 172 (5.2) | 268 (9.1) | 2,528 (4.3) | |
| Induction | 10,261 (58.9) | 4,4109 (41.2) | 7,833 (62.7) | 18,688 (41.8) | 665 (33.6) | 868 (26.2) | 1,763 (59.6) | 24,553 (41.7) | |
a
All comparisons between delivery route (cesarean vs. vaginal) were significant (p<0.01) in each group (total, nulliparas, prior cesarean, no prior cesarean except for age category (< or ≥ 35 years) and diabetes in the prior cesarean group (p>0.05)
b
Includes cases with unknown prior Cesarean status
c
103 maternal ages were missing
d
22,332 cervical dilations were missing.
BMI body mass index; SD standard deviation