Table 1.
Patient Characteristics
| Characteristic | BMI<18.5 (n=86,252) |
BMI=18.5–25 (n=1,068,211) |
BMI=25–29.9 (n=564,495) |
BMI=30–34.9 n=277,306) |
BMI=35–39.9 (n=113,818) |
BMI≥40 (n=66,591) |
P value |
|---|---|---|---|---|---|---|---|
| Age (years) | <0.001 | ||||||
| < 20 | 12,760 (14.8%) | 105,585 (9.9%) | 41,996 (7.5%) | 16,877 (6.1%) | 5401 (4.8%) | 2229 (3.3%) | |
| 20–24 | 21,278 (24.6%) | 216,606 (20.3%) | 119,755 (21.2%) | 61,273 (22.1%) | 25,286 (22.2%) | 14,003 (21%) | |
| 25–29 | 21,529 (25%) | 272,278 (25.5%) | 156,544 (27.7%) | 79,216 (28.6%) | 34,018 (29.9%) | 21,095 (31.7%) | |
| 30–34 | 18,965 (22%) | 278,241 (26%) | 143,258 (25.4%) | 69,335 (25%) | 29,313 (25.7%) | 17,823 (26.8%) | |
| 35–39 | 9654 (11.2%) | 155,924 (14.6%) | 80,858 (14.3%) | 39,716 (14.3%) | 15,696 (13.8%) | 9235 (13.9%) | |
| ≥ 40 | 2066 (2.4%) | 39,577 (3.7%) | 22,084 (3.9%) | 10,889 (3.9%) | 4104 (3.6%) | 2206 (3.3%) | |
| Race | <0.001 | ||||||
| White Non-Hispanic | 25,457 (29.5%) | 347,983 (32.6%) | 137,628 (24.4%) | 60,848 (21.9%) | 27,568 (24.2%) | 16,799 (25.2%) | |
| Black Non-Hispanic | 4,842 (5.6%) | 50,530 (4.7%) | 32,780 (5.8%) | 18,507 (6.7%) | 9201 (8.1%) | 7809 (11.7%) | |
| Asian Non-Hispanic | 22,033 (25.5%) | 150,880 (14.1%) | 33,704 (6%) | 8727 (3.2%) | 1967 (1.7%) | 536 (0.8%) | |
| Hawaiian/Pacific Islander | 3,329 (3.9%) | 42,961 (4%) | 17,635 (3.1%) | 7302 (2.6%) | 2719 (2.4%) | 1384 (2.1%) | |
| Hispanic | 30,222 (35%) | 471,398 (44.1%) | 339,796 (60.2%) | 180,081 (64.9%) | 71,414 (62.7%) | 39,291 (59%) | |
| American Indian/Alaska Native | 305 (0.4%) | 3591 (0.4%) | 2,509 (0.4%) | 1642 (0.6%) | 878 (0.8%) | 725 (1.1%) | |
| Other | 64 (0.1%) | 868 (0.1%) | 443 (0.1%) | 199 (0.1%) | 71 (0.1%) | 47 (0.1%) | |
| Insurance | <0.001 | ||||||
| Government | 40,778 (47.3%) | 463,565 (43.4%) | 304,309 (53.9%) | 161,586 (58.3%) | 64,858 (57%) | 38,814 (58.3%) | |
| Private | 41,757 (48.4%) | 570,085 (53.4%) | 245,013 (43.4%) | 109,159 (39.3%) | 46,605 (40.9%) | 26,508 (39.8%) | |
| Self-insured/Other | 3717 (4.3%) | 34,561 (3.2%) | 15,173 (2.7%) | 6561 (2.4%) | 2355 (2.1%) | 1269 (1.9%) | |
| Education | <0.001 | ||||||
| Less than High School | 17,323 (20.1%) | 214,850 (20.1%) | 157,770 (28%) | 81,048 (29.2%) | 29,057 (25.6%) | 15,118 (22.7%) | |
| High school/GED | 22,098 (25.6%) | 248,563 (23.3%) | 152,889 (27.1%) | 83,226 (30%) | 36,648 (32.2%) | 22,722 (34.1%) | |
| Some college | 14,911 (17.3%) | 182,488 (17.1%) | 106,728 (18.9%) | 58,095 (21%) | 27132 (23.8%) | 17708 (26.6%) | |
| College degree(s) | 31,920 (37%) | 422,310 (39.5%) | 147,108 (26%) | 54,937 (19.8%) | 20981 (18.4%) | 11043 (16.6%) | |
| Onset of Prenatal Care | <0.001 | ||||||
| First Trimester | 40,778 (47.3%) | 463,565 (43.4%) | 304,309 (53.9%) | 227,612 (82.1%) | 93,302 (82%) | 54,284 (81.5%) | |
| Second Trimester | 41,757 (48.4%) | 570,085 (53.4%) | 245,013 (43.4%) | 40,204 (14.5%) | 16,762 (14.7%) | 9970 (15%) | |
| Third Trimester | 3,717 (4.3%) | 34,561 (3.2%) | 15,173 (2.7%) | 9,490 (3.4%) | 3754 (3.3%) | 2337 (3.5%) | |
| Gestational Age at Delivery (weeks) | <0.001 | ||||||
| < 32 | 891 (1%) | 9,705 (0.9%) | 6,062 (1.1%) | 3,558 (1.3%) | 1699 (1.5%) | 1076 (1.6%) | |
| 32–36+6 | 6,454 (7.5%) | 66,940 (6.3%) | 36,306 (6.4%) | 19,286 (6.9%) | 8502 (7.5%) | 5523 (8.3%) | |
| 37–40+6 | 73,499 (85.2%) | 908,960 (85.1%) | 478,860 (84.8%) | 234,303 (84.5%) | 95,331 (83.7%) | 55,314 (83.1%) | |
| ≥ 41 | 5,408 (6.3%) | 82,606 (7.7%) | 43,267 (7.7%) | 20,159 (7.3%) | 8286 (7.3%) | 4678 (7%) | |
| Parity | <0.001 | ||||||
| Nulliparous | 47,142 (54.7%) | 486,349 (45.5%) | 193,897 (34.4%) | 83,269 (30%) | 33,335 (29.3%) | 19,301 (29%) | |
| Multiparous | 39,110 (45.3%) | 581,862 (54.5%) | 370,598 (65.6%) | 194,037 (70%) | 80,483 (70.7%) | 47,290 (71%) | |
| Plurality | <0.001 | ||||||
| Singleton | 85,104 (98.7%) | 1,051,255 (98.4%) | 556,037 (98.5%) | 273045 (98.5%) | 111,885 (98.3%) | 65,368 (98.2%) | |
| Multiparous | 1148 (1.3%) | 16,956 (1.6%) | 8,458 (1.5%) | 4261 (1.5%) | 1933 (1.7%) | 1223 (1.8%) | |
| Chronic Hypertension | 398 (0.5%) | 8599 (0.8%) | 10,221 (1.8%) | 9111 (3.3%) | 6337 (5.6%) | 6536 (9.8%) | <0.001 |
| Gestational Hypertension | 923 (1.1%) | 16,743 (1.6%) | 13,790 (2.4%) | 9257 (3.3%) | 4894 (4.3%) | 3572 (5.3%) | <0.001 |
| Mild Preeclampsia | 953 (1.1%) | 14,863 (1.4%) | 11,444 (2.0%) | 7423 (2.7%) | 3720 (3.3%) | 2629 (3.9%) | <0.001 |
| Severe Preeclampsia or Eclampsia | 755 (0.9%) | 10,255 (1.0%) | 6962 (1.2%) | 4085 (1.5%) | 2029 (1.8%) | 1379 (2.1%) | <0.001 |
| Fibroids | 682 (0.8%) | 13,149 (1.2%) | 7937 (1.4%) | 4188 (1.5%) | 1838 (1.6%) | 1171 (1.8%) | <0.001 |
| Diabetes Mellitus | 133 (0.1%) | 3801 (0.4%) | 4885 (0.9%) | 4678 (1.7%) | 3054 (2.7%) | 2819 (4.2%) | <0.001 |
| Previous Cesarean | 7913 (9.2%) | 140,855 (13.2%) | 104,677 (18.5%) | 62,263 (22.4%) | 29164 (25.6%) | 20134 (30.2%) | <0.001 |
| Stillbirth | 58 (0.1%) | 808 (0.1%) | 444 (0.1%) | 227 (0.08%) | 107 (0.09%) | 69 (0.1%) | 0.04 |
| Previa | 604 (0.7%) | 7526 (0.7%) | 3651 (0.7%) | 1,606 (0.6%) | 585 (0.5%) | 302 (0.5%) | <0.001 |
| Prolonged Labor | 1171 (1.3%) | 13,852 (1.3%) | 5107 (0.9%) | 1,912 (0.7%) | 730 (0.6%) | 397 (0.6%) | <0.001 |
| Labor | 31,935 (37%) | 396,640 (37.1%) | 206,787 (36.6%) | 102,272 (36.9%) | 42168 (37.1%) | 25104 (37.7%) | <0.001 |
| Chorioamnionitis | 1801 (2.1%) | 24,976 (2.3%) | 12,615 (2.2%) | 5,532 (2%) | 2140 (1.9%) | 1198 (1.8%) | <0.001 |
| Abruption | 903 (1.1%) | 9,355 (0.9%) | 4699 (0.8%) | 2,356 (0.9%) | 978 (0.9%) | 544 (0.8%) | <0.001 |
| Polyhydramnios | 236 (0.3%) | 4087 (0.4%) | 2758 (0.5%) | 1,744 (0.6%) | 876 (0.8%) | 633 (0.9%) | <0.001 |
| Induction | 10,888 (12.6%) | 152,078 (14.2%) | 86,149 (15.3%) | 45,403 (16.4%) | 20,322 (17.9%) | 12,473 (18.7%) | <0.001 |
| Mode of Delivery | <0.001 | ||||||
| Vaginal | 61,438 (71.2%) | 721,708 (67.6%) | 355,529 (63%) | 161,243 (58.1%) | 59,932 (52.6%) | 29,791 (44.7%) | |
| Assisted Vaginal | 4887 (5.7%) | 46,242 (4.3%) | 16,840 (3%) | 6264 (2.3%) | 2119 (1.9%) | 1043 (1.6%) | |
| Cesarean | 19,927 (23.1%) | 300,261 (28.1%) | 192,126 (34%) | 109,799 (39.6%) | 51,767 (45.5%) | 35,757 (53.7%) |
Data presented as n (%)
BMI = body mass index; GED = graduate educational test.