Table 2.
Demographic characteristics, preterm birth, and labor type of the study population, New York City, 2008–2010 [n (%)].
| Characteristic | Total | Preterm (< 37 weeks) | Early preterm (< 32 weeks) | |
|---|---|---|---|---|
| Spontaneous | Medically indicated | |||
| Infant sex, male | 132,654 (51) | 6,543 (54) | 3,728 (54) | 1,536 (53) |
| Parity | ||||
| 0 | 120,395 (47) | 5,436 (45) | 3,273 (48) | 1,456 (50) |
| 1 | 75,976 (29) | 3,386 (28) | 1,810 (26) | 723 (25) |
| 2 | 35,045 (14) | 1,799 (15) | 982 (14) | 418 (14) |
| ≥ 3 | 26,878 (10) | 1,513 (12) | 814 (12) | 314 (11) |
| Maternal ethnicity | ||||
| Non-Hispanic white | 71,085 (28) | 1,988 (16) | 1,393 (20) | 352 (12) |
| Foreign-born non-Hispanic black | 24,999 (10) | 1,565 (13) | 912 (13) | 481 (17) |
| U.S.-born non-Hispanic black | 31,219 (12) | 2,399 (20) | 1,195 (17) | 804 (28) |
| Foreign-born Hispanic | 55,209 (21) | 2,493 (21) | 1,361 (20) | 512 (18) |
| U.S.-born Hispanic | 32,026 (12) | 1,870 (15) | 992 (14) | 442 (15) |
| Foreign-born Asian | 35,227 (14) | 1,385 (11) | 789 (11) | 239 (8) |
| U.S.-born Asian | 3,017 (1) | 131 (1) | 80 (1) | 21 (1) |
| Other | 5,243 (2) | 289 (2) | 147 (2) | 56 (2) |
| Unknown | 269 (0) | 14 (0) | 10 (0) | 4 (0) |
| Maternal education (years) | ||||
| < 9 | 20,712 (8) | 1,001 (8) | 492 (7) | 210 (7) |
| 9–11 | 45,495 (18) | 2,561 (21) | 1,354 (20) | 645 (22) |
| 12 | 61,808 (24) | 2,998 (25) | 1,702 (25) | 744 (26) |
| 13–15 | 56,971 (22) | 2,895 (24) | 1,738 (25) | 795 (27) |
| 16 | 41,848 (16) | 1,621 (13) | 921 (13) | 334 (11) |
| > 16 | 31,460 (12) | 1,058 (9) | 672 (10) | 183 (6) |
| Maternal age (years) | ||||
| < 20 | 17,065 (7) | 954 (8) | 518 (8) | 238 (8) |
| 20 to < 25 | 53,233 (21) | 2,410 (20) | 1,371 (20) | 613 (21) |
| 25 to < 30 | 68,101 (26) | 2,910 (24) | 1,672 (24) | 663 (23) |
| 30 to < 35 | 68,376 (26) | 3,044 (25) | 1,757 (26) | 714 (25) |
| 35 to < 40 | 39,918 (15) | 2,044 (17) | 1,164 (17) | 514 (18) |
| ≥ 40 | 11,601 (4) | 772 (6) | 397 (6) | 169 (6) |
| Mother on Medicaid | 157,629 (61) | 7,773 (64) | 4,344 (63) | 1,892 (65) |
| Year of conception | ||||
| 2007 | 43,205 (17) | 2,065 (17) | 1,153 (17) | 455 (16) |
| 2008 | 99,569 (39) | 4,749 (39) | 2,675 (39) | 1,181 (41) |
| 2009 | 96,124 (37) | 4,419 (36) | 2,536 (37) | 1,052 (36) |
| 2010 | 19,396 (8) | 901 (7) | 515 (7) | 223 (8) |
| Maternal prepregnancy body mass index | ||||
| < 18.5 | 14,264 (6) | 655 (5) | 356 (5) | 129 (4) |
| 18.5 to < 25 | 139,480 (54) | 5,878 (48) | 3,223 (47) | 1,234 (42) |
| 25 to < 30 | 61,388 (24) | 3,075 (25) | 1,735 (25) | 818 (28) |
| ≥ 30 | 43,162 (17) | 2,526 (21) | 1,565 (23) | 730 (25) |
| Total births | 258,294 (100) | 12,134 (100) | 6,879 (100) | 2,911 (100) |