Table 1.
Maternal and Obstetric Characteristics by Maternal Age Category
| Characteristic | Younger Than 20.0 y (n = 19,638) | 20.0–24.9 y (n = 51,011) | 25.0–29.9 y (n = 56,480) | 30.0–34.9 y (n = 45,715) | 35.0–39.9 y (n = 24,351) | 40.0–44.9 y (n = 5,931) | 45.0 y or Older (n = 391) |
|---|---|---|---|---|---|---|---|
| Age (y) | 17.8±1.3 | 22.1±1.4 | 27.0±1.4 | 31.9±1.4 | 36.6±1.4 | 41.2±1.2 | 46.1±1.8 |
| Race* | |||||||
| Non-Hispanic white | 5,266 (26.8) | 22,515 (44.1) | 29,801 (52.8) | 25,483 (55.7) | 13,516 (55.5) | 3,085 (52.0) | 214 (54.7) |
| Non-Hispanic black | 8,090 (41.2) | 14,264 (28.0) | 10,791 (19.1) | 7,310 (16.0) | 4,058 (16.7) | 1,166 (19.7) | 83 (21.2) |
| Hispanic | 4,721 (24.0) | 9,593 (18.8) | 9,550 (16.9) | 7,101 (15.5) | 3,708 (15.2) | 958 (16.2) | 50 (12.8) |
| Asian or Pacific Islander | 166 (0.85) | 1,183 (2.3) | 2,573 (4.6) | 2,760 (6.0) | 1,405 (5.8) | 322 (5.4) | 17 (4.4) |
| Other or unknown | 1,395 (7.1) | 3,456 (6.8) | 3,765 (6.7) | 3,061 (6.7) | 1,664 (6.8) | 400 (6.7) | 27 (6.9) |
| Gravidity* | 1 (1, 2) | 2 (1, 3) | 2 (1, 3) | 3 (2, 4) | 3 (2, 4) | 4 (2, 5) | 4 (2, 6) |
| Parity and previous uterine scar* | |||||||
| Nulliparous, no scar | 16,702 (85.1) | 28,829 (56.5) | 21,080 (37.3) | 14,184 (31.0) | 6,434 (26.4) | 1,478 (24.9) | 117 (29.9) |
| Multiparous, no scar | 2,467 (12.6) | 17,955 (35.2) | 28,215 (50.0) | 23,717 (51.9) | 12,793 (52.5) | 3,106 (52.4) | 173 (44.3) |
| Multiparous, previous scar | 469 (2.4) | 4,227 (8.3) | 7,185 (12.7) | 7,814 (17.1) | 5,124 (21.0) | 1,347 (22.7) | 101 (25.8) |
| BMI at admission,* (kg/m2) (missing data = 42,017) | 29.9±5.9 (n = 15,540) | 30.8±6.3 (n = 40,316) | 31.1±6.3 (n = 45,355) | 31.0±6.2 (n = 36,178) | 31.0±6.3 (n = 19,138) | 31.0±6.0 (n = 4,675) | 31.3±6.0 (n = 298) |
| Insurance* | |||||||
| Private | 5,648 (28.8) | 22,349 (43.8) | 34,480 (61.1) | 30,753 (67.3) | 15,966 (65.6) | 3,634 (61.3) | 227 (58.1) |
| Public or self-pay | 12,044 (61.3) | 24,297 (47.6) | 16,828 (29.8) | 9,420 (20.6) | 4,557 (18.7) | 1,178 (19.9) | 84 (21.5) |
| Other or unknown | 1,946 (9.9) | 4,365 (8.6) | 5,172 (9.2) | 5,542 (12.1) | 3,828 (15.7) | 1,119 (18.9) | 80 (20.5) |
| Tobacco use* | 1,615 (8.2) | 4,483 (8.8) | 3,771 (6.7) | 2,238 (4.9) | 1,232 (5.1) | 360 (6.1) | 18 (4.6) |
| Alcohol use* | 349 (1.8) | 1,022 (2.0) | 995 (1.8) | 774 (1.7) | 502 (2.1) | 131 (2.2) | 7 (1.8) |
| Drug use* (missing data = 21,205) | 500 (2.9) (n = 17,175) | 1,126 (2.5) (n = 45,640) | 979 (1.9) (n = 50,743) | 689 (1.7) (n = 40,914) | 414 (1.9) (n = 21,993) | 139 (2.5) (n = 5,484) | 5 (1.4) (n = 363) |
| Pre-existing medical conditions | |||||||
| Pregestational diabetes* | 182 (0.9) | 617 (1.2) | 1,142 (2.0) | 1,317 (2.9) | 972 (4.0) | 280 (4.7) | 21 (5.4) |
| Chronic hypertension* | 431 (2.2) | 1,049 (2.1) | 1,406 (2.5) | 1,532 (3.4) | 1,171 (4.8) | 456 (7.7) | 37 (9.5) |
| Cardiac disease* (missing data = 7,321) | 127 (0.7) (n = 18,346) | 307 (0.6) (n = 48,521) | 352 (0.6) (n = 54,583) | 368 (0.8) (n = 44,644) | 212 (0.9) (n = 23,871) | 71 (1.2) (n = 5,847) | 9 (2.3) (n = 384) |
| Asthma* | 2,018 (10.3) | 3,927 (7.7) | 3,544 (6.3) | 2,413 (5.3) | 1,240 (5.1) | 284 (4.8) | 16 (4.1) |
| Renal disease* (missing data = 7,321) | 193 (1.1) (n = 18,346) | 452 (0.9) (n = 48,521) | 359 (0.7) (n = 54,583) | 295 (0.7) (n = 44,644) | 118 (0.5) (n = 23,871) | 21 (0.4) (n = 5,847) | 2 (0.5) (n = 384) |
| Neurologic disease† (missing data = 23,022) | 33 (0.2) (n = 16,560) | 52 (0.1) (n = 44,780) | 43 (0.1) (n = 50,860) | 39 (0.1) (n = 41,254) | 18 (0.1) (n = 21,600) | 9 (0.2) (n = 5,095) | 0 (n = 346) |
BMI, body mass index.
Data are mean±standard deviation, n (%), or median (interquartile range).
*
P<.001.
†
P=.003.