Relation of infant, maternal, and pregnancy/delivery characteristics to the development of a post-discharge TSB >95th centile*
| Variables | Overall | Post-discharge TSB >95th centile | p value | OR (95% CI) | |
|---|---|---|---|---|---|
| No (n = 801) | Yes (n = 98) | ||||
| *Gestational age based on Ballard score and obstetrical dating of pregnancy rounded to the nearest week; small for gestational age (SGA) defined as birth weight for gestational age below the 10th centile and large for gestational age (LGA) as at or above the 90th centile (stratified by sex and race);26 maternal race was self-reported at the time of registration and documented in administrative records; planned method of feeding was reported by mothers to nurses at discharge and documented in discharge instruction forms; gestational diabetes diagnosis based on glucose tolerance test (GTT) results; parity figure does not include infant delivered at birth hospitalisation; vaginal bleeding refers to bleeding occurring after 20 weeks of pregnancy; prolonged rupture of membranes defined as greater than 18 hours; use of oxytocin for induction or augmentation (but not post-partum) defines oxytocin exposure. | |||||
| †Reference group for OR and p value calculations. | |||||
| Infant | |||||
| Male (no., %) | 471 (52) | 418 (52) | 53 (54) | 0.72 | 1.1 (0.7 to 1.6) |
| Cephalohaematoma (no., %) | 55 (6) | 49 (6) | 6 (6) | 0.97 | 1.0 (0.4 to 2.4) |
| Bruising (no., %) | 41 (5) | 36 (4) | 5 (5) | 0.80 | 1.2 (0.4 to 3.0) |
| Gestational age (no., %) | |||||
| <38 wk | 179 (20) | 152 (19) | 27 (28) | 0.02 | 1.9 (1.1 to 3.1) |
| 38–39 wk† | 493 (55) | 450 (56) | 43 (44) | – | – |
| ⩾40 wk | 227 (25) | 199 (25) | 28 (29) | 0.13 | 1.5 (0.9 to 2.4) |
| Size for gestational age (no., %) | |||||
| SGA | 69 (8) | 68 (9) | 1 (1) | 0.04 | 0.1 (0.02 to 0.9) |
| AGA† | 739 (82) | 657 (82) | 82 (84) | – | – |
| LGA | 91 (10) | 76 (10) | 15 (15) | 0.13 | 1.6 (0.9 to 2.9) |
| Pre-discharge TSB (no., %) | |||||
| <40th centile† | 172 (19) | 171 (21) | 1 (1) | – | – |
| 40th–75th centile | 398 (44) | 388 (48) | 10 (10) | 0.16 | 4.4 (0.6 to 35) |
| 76th–95th centile | 273 (30) | 216 (27) | 57 (58) | <0.001 | 45 (6.2 to 329) |
| >95th centile | 56 (6) | 26 (3) | 30 (31) | <0.001 | 197 (26 to 1509) |
| Birth weight, kg (mean (SD)) | 3.3 (0.5) | 3.3 (0.5) | 3.4 (0.5) | 0.008 | 1.8 (1.2 to 2.8) |
| % weight loss/day (mean (SD)) | 2.1 (1.6) | 2.1 (1.5) | 2.1 (2.4) | 0.97 | 1.0 (0.9 to 1.1) |
| Maternal | |||||
| Race/ethnicity (no., %) | |||||
| White† | 390 (43) | 345 (43) | 45 (46) | – | – |
| Black | 351 (39) | 320 (40) | 31 (32) | 0.23 | 0.7 (0.5 to 1.2) |
| Hispanic | 39 (4) | 36 (5) | 3 (3) | 0.47 | 0.6 (0.2 to 2.2) |
| Asian | 72 (8) | 62 (8) | 10 (10) | 0.57 | 1.2 (0.6 to 2.6) |
| Others | 46 (5) | 38 (5) | 8 (8) | 0.25 | 1.6 (0.7 to 3.7) |
| Method of feeding | |||||
| Breast | 461 (51) | 397 (50) | 64 (65) | <0.001 | 2.5 (1.5 to 4.2) |
| Bottle† | 332 (37) | 312 (39) | 20 (20) | – | |
| Both | 104 (12) | 90 (11) | 14 (14) | 0.02 | 2.4 (1.2 to 5.0) |
| Hypertension (no., %) | 19 (2) | 16 (2) | 3 (3) | 0.44 | 1.6 (0.5 to 5.6) |
| Diabetes mellitus (no., %) | 24 (3) | 19 (3) | 5 (6) | 0.17 | 2.3 (0.8 to 6.2) |
| Age (mean (SD)) | 28.5 (6.3) | 28.4 (6.3) | 29.2 (6.1) | 0.22 | 1.02 (0.99 to 1.06) |
| Parity (mean (SD)) | 1.0 (1.2) | 1.0 (1.3) | 0.7 (1.0) | 0.03 | 0.8 (0.6 to 0.98) |
| Pregnancy and delivery | |||||
| Vaginal bleeding (no., %) | 3 (0.4) | 3 (0.4) | 0 (0) | 0.98 | 0 |
| Smoked (no., %) | 69 (8) | 63 (8) | 6 (6) | 0.53 | 0.8 (0.3 to 1.8) |
| Caesarean section (no., %) | 101 (11) | 94 (12) | 7 (7) | 0.18 | 0.6 (0.3 to 1.3) |
| Forceps (no., %) | 42 (5) | 39 (5) | 3 (3) | 0.61 | 0.6 (0.2 to 2.1) |
| Vacuum (no., %) | 133 (15) | 107 (13) | 26 (27) | <0.001 | 2.4 (1.4 to 3.9) |
| Prolonged rupture of membranes (no., %) | 35 (4) | 28 (4) | 7 (7) | 0.08 | 2.1 (0.9 to 5.0) |
| Oxytocin (no., %) | 542 (61) | 469 (60) | 73 (75) | 0.002 | 2.1 (1.3 to 3.4) |
| Epidural (no., %) | 635 (71) | 562 (71) | 73 (75) | 0.35 | 1.3 (0.8 to 2.1) |