Table 1. Characteristics of study population by degree of prematurity.
| Extremely Preterm (<30 weeks) | Moderately Preterm (30–33 weeks) | Late Preterm (34–36 weeks) | Total Population | |
|---|---|---|---|---|
| N = 548 (21.34%) | N = 751 (29.24%) | N = 1,269 (49.42%) | N = 2,568 | |
| n (%) | n (%) | n (%) | n (%) | |
| Maternal characteristics and clinical factors | ||||
| Maternal race | ||||
| Asian | 16 (2.92%) | 17 (2.26%) | 54 (4.26%) | 87 (3.39%) |
| Black/African American | 75 (13.69%) | 53 (7.06%) | 109 (8.59%) | 237 (9.23%) |
| Multiple Race | 12 (2.19%) | 10 (1.33%) | 22 (1.73%) | 44 (1.71%) |
| Other | 35 (6.39%) | 45 (5.99%) | 99 (7.80%) | 179 (6.97%) |
| Unknown | 19 (3.47%) | 16 (2.13%) | 33 (2.60%) | 68 (2.65%) |
| White | 391 (71.35%) | 610 (81.23%) | 952 (75.02%) | 1953 (76.05%) |
| Maternal ethnicity | ||||
| Hispanic or Latino | 30–40 (<10%)† | 50–60 (<10%)† | 102 (8.04%) | 187 (7.28%) |
| Not Hispanic/Latino | 455 (83.03%) | 647 (86.15%) | 1103 (86.92%) | 2205 (85.86%) |
| Other | <10 (<10%)† | <10 (<10%)† | 19 (1.50%) | 35 (1.36%) |
| Unknown | 49 (8.94%) | 47 (6.26%) | 45 (3.55%) | 141 (5.49%) |
| Mother’s age (years)‡ | 29.26 ± 5.96 | 29.76 ± 5.87 | 30.02 ± 5.66 | 29.78 ± 5.79 |
| Maternal primary insurance at delivery | ||||
| Medicaid | 187 (34.12%) | 233 (31.03%) | 339 (26.71%) | 759 (29.56%) |
| Medicare | <10 (<15%)† | <10 (<10%)† | 12 (0.95%) | 22 (0. 68%) |
| Other | 14 (2.55%) | 23 (3.06%) | 32 (2.52%) | 69 (2.69%) |
| Private | 285 (52.01%) | 418 (55.66%) | 755 (59.50%) | 1458 (56.78%) |
| Unknown | 60–70 (<15%)† | 60–70 (<10%)† | 131 (10.32%) | 260 (10.12%) |
| Maternal first trimester BMI | ||||
| Underweight | <10 (<10%)† | <15 (<10%)† | 23 (1.81%) | 39 (1.52%) |
| Normal BMI | 196 (35.77%) | 296 (39.28%) | 461 (36.33%) | 952 (37.07%) |
| Overweight | <150 (<25%)† | <180 (<25%)† | 327 (25.77%) | 635 (24.73% |
| Obese | 212 (38.69%) | 272 (36.22%) | 458 (36.09%) | 942 (36.68%) |
| Chorioamnionitis | 76 (13.87%) | 44 (5.86%) | 38 (2.99%) | 158 (6.15%) |
| Depression during pregnancy or prior to child’s discharge | 106 (19.34%) | 131 (17.44%) | 209 (16.47%) | 446 (17.37%) |
| Diabetes during pregnancy | 62 (11.31%) | 143 (19.04%) | 308 (24.27%) | 513 (19.98%) |
| Hypertension during pregnancy | 86 (15.69%) | 216 (28.76%) | 353 (27.82%) | 655 (25.51%) |
| Preeclampsia | 88 (16.06%) | 233 (31.03%) | 338 (26.64%) | 659 (25.66%) |
| Birth and neonatal characteristics | ||||
| Sex | ||||
| Female | 297 (54.20%) | 339 (45.14%) | 546 (43.03%) | 1182 (46.03%) |
| Male | 251 (45.80%) | 412 (54.86%) | 723 (56.97%) | 1386 (53.97%) |
| Birth year | ||||
| 2009 | 32 (5.84%) | 44 (5.86%) | 80 (6.30%) | 156 (6.07%) |
| 2010 | 60 (10.95%) | 92 (12.25%) | 132 (10.40%) | 284 (11.06%) |
| 2011 | 58 (10.58%) | 57 (7.59%) | 131 (10.32%) | 246 (9.58%) |
| 2012 | 58 (10.58%) | 91 (12.12%) | 157 (12.37%) | 306 (11.92%) |
| 2013 | 65 (11.86%) | 81 (10.79%) | 125 (9.85%) | 271 (10.55%) |
| 2014 | 63 (11.50%) | 87 (11.58%) | 160 (12.61%) | 310 (12.07%) |
| 2015 | 66 (12.04%) | 93 (12.38%) | 143 (11.27%) | 302 (11.76%) |
| 2016 | 72 (13.14%) | 106 (14.11%) | 137 (10.80%) | 315 (12.27%) |
| 2017 | 64 (11.68%) | 82 (10.92%) | 167 (13.16%) | 313 (12.19%) |
| 2018 | 10 (1.82%) | 18 (2.40%) | 37 (2.92%) | 65 (2.53%) |
| Multiples | 144 (26.28%) | 278 (37.02%) | 376 (29.63%) | 798 (31.07%) |
| Delivery Type | ||||
| Cesarean Section | 367 (66.97%) | 486 (64.71%) | 675 (53.19%) | 1528 (59.50%) |
| Vaginal | 181 (33.03%) | 265 (35.29%) | 594 (46.81%) | 1040 (40.50%) |
| Birth length (cm)‡ | 34.51 ± 3.96 | 42.39 ± 3.47 | 46.83 ± 2.80 | 42.90 ± 5.78 |
| Birth weight (gr)‡ | 951.61 ± 298.47 | 1747.17 ± 416.31 | 2536.43 ± 506.99 | 1967.42 ± 768.84 |
| Head circumference (cm)‡ | 24.36 ± 2.75 | 29.69 ± 2.18 | 32.54 ± 1.73 | 29.96 ± 3.81 |
| 1-minute Apgar score‡ | 5 ± 2 | 6 ± 2 | 7 ± 2 | 6 ± 2 |
| Length of birth hospitalization stay (days)‡ | 89.80 ± 40.18 | 36.36 ± 22.37 | 11.64 ± 10.55 | 35.55 ± 38.16 |
| Neonatal morbidities and treatments | ||||
| Atrial septal defects | 323 (58.94%) | 136 (18.11%) | 122 (9.61%) | 581 (22.62%) |
| BPD | 412 (75.18%) | 75 (9.99%) | 17 (1.34%) | 504 (19.63%) |
| Hypoglycemic | 243 (44.34%) | 407 (54.19%) | 690 (54.37%) | 1340 (52.18%) |
| Hyperglycemic | 215 (39.23%) | 65 (8.66%) | 32 (2.52%) | 312 (12.15%) |
| IVH | 97 (17.70%) | 50–60 (<10%)† | <10 (<10%)† | 154 (6.00%) |
| NEC | 20 (3.65%) | 10–20 (<10%)† | <10 (<10%)† | 40 (1.56%) |
| PDA | 280 (51.09%) | 41 (5.46%) | 29 (2.29%) | 350 (13.63%) |
| PVL | 22 (4.01%) | <10 (<10%)† | <10 (<10%)† | 29 (1.13%) |
| RDS | 514 (93.80%) | 412 (54.86%) | 363 (28.61%) | 1289 (50.19%) |
| ROP | 219 (39.96%) | 10–20 (<10%)† | <10 (<10%)† | 229 (8.92%) |
| Ventricular septal defects | 22 (4.01%) | 12 (1.60%) | 26 (2.05%) | 60 (2.34%) |
| TPN | 536 (97.81%) | 684 (91.08%) | 256 (20.17%) | 1476 (57.48%) |
Abbreviations: BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; NEC, necrotizing enterocolitis; PDA, patent ductus arteriosus; PVL, periventricular leukomalacia; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; TPN, total parenteral nutrition; gr, grams; cm, centimeters.
†Values given as a range, as data is suppressed due to counts less than 10 or to protect confidentiality.
‡Data are expressed as mean ± standard deviation.