From: Prenatal tobacco smoke exposure increases hospitalizations for bronchiolitis in infants
 |  | Prenatal smoking exposure | Postnatal smoking exposure | |||||
---|---|---|---|---|---|---|---|---|
 |  |  | Passive | Active maternal smoking |  |  |  | |
Newborn and parents’ characteristics | Total | None | maternal smoking | ≤15 cig/day | >15 cig/day | None | Out of living environment | In living environment |
Socio demographic characteristics of parents | Â | Â | Â | Â | Â | Â | Â | Â |
 Mother’s Age | 33.6 ± 5.3 | 33.9 ± 5.2 | 32.9 ± 5.1 | 32.5 ± 5.8 | 34.0 ± 5.5 | 34.1 ± 5.2 | 32.8 ± 5.3 | 33.5 ± 5.5 |
 (y, mean ± SD) | ||||||||
 Parents’ Educational Level |  |  |  |  |  |  |  |  |
  Primary, N. (%) | 270 | 159 (9.7) | 50 (14.9) | 50 (26.3) | 11 (27.5) | 115 (8.8) | 136 (17.1) | 19 (17.6) |
  High, N. (%) | 1521 | 1122 (68.2) | 243 (72.3) | 128 (67.4) | 28 (70.0) | 885 (67.7) | 564 (71.0) | 72 (66.7) |
  Graduate, N. (%) | 419 | 363 (22.1) | 43 (12.8) | 12 (6.3) | 1 (2.5) | 308 (23.5) | 94 (11.8) | 17 (15.7) |
Gestational Age at birth | Â | Â | Â | Â | Â | Â | Â | Â |
 Weeks |  |  |  |  |  |  |  |  |
  33–34, N. (%) | 737 | 559 (34.0) | 102 (30.4) | 60 (31.6) | 16 (40.0) | 427 (32.6) | 273 (34.4) | 37 (34.3) |
  35–37, N. (%) | 767 | 560 (34.1) | 114 (33.9) | 81 (42.6) | 12 (30.0) | 447 (34.2) | 279 (35.1) | 41 (38.0) |
   > 37, N. (%) | 706 | 525 (31.9) | 120 (35.7) | 49 (25.8) | 12 (30.0) | 434 (33.2) | 242 (30.5) | 30 (27.8) |
Risk conditions | Â | Â | Â | Â | Â | Â | Â | Â |
  Prenatal Risk | 2092 | 1551 (94.3) | 323 (96.1) | 180 (94.7) | 38 (95.0) | 1231 (94.1) | 760 (95.7) | 101 (93.5) |
  Neonatal Risk | 1945 | 1445 (88.5) | 299 (89.0) | 165 (86.8) | 36 (90) | 1137 (86.9) | 712 (89.7) | 96 (88.9) |
Environmental risk conditions | Â | Â | Â | Â | Â | Â | Â | Â |
  Exposure to Epidemic Season | 1323 | 998 (60.7) | 196 (58.3) | 108 (56.8) | 21 (52.5) | 790 (60.4) | 455 (57.3) | 78 (72.2) |
  No Breastfeeding | 482 | 352 (21.4) | 70 (20.8) | 45 (23.7) | 15 (37.5) | 289 (22.1) | 169 (21.3) | 24 (22.2) |
  Siblings | 900 | 644 (39.2) | 145 (43.2) | 89 (46.8) | 22 (55.0) | 520 (39.8) | 330 (41.6) | 50 (46.3) |
  Crowded Living | 227 | 160 (9.7) | 35 (10.4) | 25 (13.2) | 7 (17.5) | 141 (10.8) | 68 (8.6) | 18 (16.7) |
  Day Care Atten dance Attendance | 357 | 265 (16.1) | 43 (12.8) | 43 (22.6) | 6 (15.0) | 221 (16.9) | 117 (14.7) | 19 (17.6) |
Hospitalizations for bronchiolitis (%) | 120 (5.4) | 77 (4.7) | 26 (7.7) | 11 (5.8) | 6 (15.0) | 65 (5.0) | 47 (5.9) | 8 (7.4) |
TOTAL | 2210 | 1644 | 336 | 190 | 40 | 1308 | 794 | 108 |