Table 1.
Patients’ characteristics. Values are numbers (percentages)
| Characteristic | All (n=6 704 311) | Cesarean delivery (n=2 013 575) | Vaginal delivery (n=4 690 736) |
|---|---|---|---|
| Age: | |||
| ≤20 years | 903 890 (13.5) | 189 095 (9.4) | 714 795 (15.2) |
| 21-25 years | 1 538 276 (23.0) | 386 569 (19.2) | 1 151 707 (24.6) |
| 26-30 years | 1 841 457 (27.5) | 541 942 (26.9) | 1 299 515 (27.7) |
| 31-35 years | 1 579 850 (23.6) | 544 668 (27.1) | 1 035 182 (22.1) |
| ≥35 years | 840 838 (12.5) | 351 301 (17.4) | 489 537 (10.4) |
| Race/ethnicity: | |||
| Not non-Hispanic white | 3 112 223 (46.4) | 949 294 (47.1) | 2 162 929 (46.1) |
| Missing race/ethnicity | 238 822 (3.6) | 64 333 (3.2) | 174 489 (3.7) |
| Medicaid or no insurance | 3 032 889 (45.2) | 827 235 (41.1) | 2 205 654 (47.0) |
| Admitted on Saturday or Sunday | 1 368 994 (20.4) | 299 163 (14.9) | 1 069 831 (22.8) |
| Previous cesarean section | 949 068 (14.2) | 784 086 (38.9) | 164 982 (3.5) |
| Comorbidities: | |||
| Fetal malpresentation | 425 716 (6.4) | 335 754 (16.7) | 89 962 (1.9) |
| Antepartum bleeding | 116 048 (1.7) | 81 160 (4.0) | 34 888 (0.7) |
| Herpes, HIV, hepatitis, human papillomavirus, other viral illnesses | 101 763 (1.5) | 48 653 (2.4) | 53 110 (1.1) |
| Severe hypertension | 74 699 (1.1) | 51 755 (2.6) | 22 944 (0.5) |
| Uterine scar unrelated to cesarean section | 13 144 (0.2) | 11 812 (0.6) | 1332 (0.0) |
| Multiple gestation | 87 737 (1.3) | 61 041 (3.0) | 26 696 (0.6) |
| Macrosomia | 171 383 (2.6) | 106 866 (5.3) | 64 517 (1.4) |
| Unengaged fetal head | 102 840 (1.5) | 98 601 (4.9) | 4239 (0.1) |
| Maternal soft tissue disorder | 198 694 (3.0) | 138 569 (6.9) | 60 125 (1.3) |
| Other types of hypertension | 431 820 (6.4) | 189 631 (9.4) | 242 189 (5.2) |
| Preterm gestation | 480 502 (7.2) | 197 689 (9.8) | 282 813 (6.0) |
| Congenital fetal central nervous system anomaly or chromosomal abnormality | 5910 (0.1) | 3254 (0.2) | 2656 (0.1) |
| Asthma | 137 057 (2.0) | 52 428 (2.6) | 84 629 (1.8) |
| Maternal renal abnormality | 8784 (0.1) | 3577 (0.2) | 5207 (0.1) |
| Maternal liver abnormality | 6356 (0.1) | 2240 (0.1) | 4116 (0.1) |
| Diabetes or abnormal glucose tolerance | 47 483 (0.7) | 18 879 (0.9) | 28 604 (0.6) |
| Maternal thyroid abnormality | 100 301 (1.5) | 40 181 (2.0) | 60 120 (1.3) |
| Maternal substance misuse | 19 673 (0.3) | 5625 (0.3) | 14 048 (0.3) |
| Maternal mental disorder | 158 262 (2.4) | 53 754 (2.7) | 104 508 (2.2) |
| Maternal congenital and other heart disease | 93 040 (1.4) | 33 735 (1.7) | 59 305 (1.3) |
| Isoimmunization | 127 330 (1.9) | 38 594 (1.9) | 88 736 (1.9) |
| Intrauterine fetal demise | 2894 (0.0) | 638 (0.0) | 2256 (0.1) |
| Intrauterine growth restriction | 98 538 (1.5) | 47 359 (2.4) | 51 179 (1.1) |
| Oligohydramnios | 42 687 (0.6) | 24 372 (1.2) | 18 315 (0.4) |
| Polyhydramnios | 215 045 (3.2) | 92 708 (4.6) | 122 337 (2.6) |
| Ruptured membrane >24 hours | 105 478 (1.6) | 38 186 (1.9) | 67 292 (1.4) |
| Chorioamnionitis | 120 616 (1.8) | 65 156 (3.2) | 55 460 (1.2) |
| Other maternal infection | 70 929 (1.1) | 25 155 (1.2) | 45 774 (1.0) |
| Uterine rupture | 4351 (0.1) | 3781 (0.2) | 570 (0.0) |
| Maternal obesity | 59 413 (0.9) | 37 293 (1.9) | 22 120 (0.5) |