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Table 4 Perinatal outcomes in Western Australia (2000–2013) and New South Wales (2002–2008) by plurality and Aboriginality

From: Pregnancy and birth characteristics of Aboriginal twins in two Australian states: a data linkage study

  Western Australia
(2000–2013)
New South Wales
(2002–2008)
Aboriginal Aboriginal Non-Aboriginal
Perinatal outcomes Twin
N = 880
n (%)
Singleton
N = 33,229
n (%)
Twin
N = 794
n (%)
Singleton
N = 31,524
n (%)
Twin
N = 18,338
n (%)
Singleton
N = 582,355
n (%)
Groups compared and statistical significance reported1 A A B B C C
   D   D  
All births N = 880 N = 33,229 N = 794 N = 31,524 N = 18,338 N = 582,355
 StillbirthaC 20 (2) 398 (1) 10 (1) 262 (1) 332 (2) 3295 (1)
Live births only N = 860 N = 32,831 N = 784 N = 31,262 N = 18,006 N = 579,060
 Neonatal deathABC 29 (3) 147 (< 1) 20 (3) 105 (< 1) 294 (2) 1182 (< 1)
 Birth weight (grams) (mean (SD)) 2225 (682) 3207 (636) 2311 (661) 3283 (622) 2436 (605) 3419 (545)
 Birth weight bands ABCD
  < 1000 59 (7) 252 (1) 35 (4) 174 (1) 535 (3) 1673 (< 1)
  1000–1499 67 (8) 315 (1) 67 (9) 224 (1) 840 (5) 2070 (< 1)
  1500–1999 153 (18) 709 (2) 101 (13) 549 (2) 2213 (12) 4458 (1)
  2000–2499 240 (28) 2292 (7) 239 (31) 1895 (6) 5101 (28) 16,228 (3)
  2500–2999 248 (29) 7097 (22) 251 (32) 5970 (19) 6477 (36) 81,429 (14)
  3000–3499 88 (10) 11,544 (35) 72 (9) 10,742 (34) 2498 (14) 212,821 (37)
  3500+ 5 (1) 10,622 (32) 18 (2) 11,695 (37) 320 (2) 260,131 (45)
 Gestational age (median (IQR)) 36 (33, 37) 39 (38, 40) 36 (34, 37) 39 (38, 40) 37 (35, 38) 39 (38, 40)
 Gestational age categories ABCD
  20–23 22 (3) 62 (< 1) 9 (1) 52 (< 1) 152 (1) 479 (< 1)
  24–27 30 (3) 183 (1) 24 (3) 139 (< 1) 345 (2) 1200 (< 1)
  28–31 68 (8) 414 (1) 75 (10) 261 (1) 1001 (6) 2712 (< 1)
  32–34 198 (23) 922 (3) 126 (16) 743 (2) 2658 (15) 7137 (1)
  35–36 240 (28) 2329 (7) 211 (27) 1638 (5) 4475 (25) 18,783 (3)
  37–38 279 (32) 10,030 (31) 292 (38) 7119 (23) 8216 (46) 124,134 (21)
  39+ 23 (3) 18,846 (57) 31 (4) 21,298 (68) 861 (5) 424,508 (73)
 ResuscitationABC 449 (52) 11,170 (34) 455 (58) 13,190 (42) 10,463 (58) 235,578 (41)
 Length of stay (median (IQR) in days)A 7 (4–14) 3 (2–4)
 Admitted to NICU or SCN2,ABCd 452 (64) 4343 (29) 500 (64) 5984 (19) 10,521 (57) 82,257 (14)
 Cerebral palsy. 5 (1) 114 (< 1)
 Respiratory distress syndrome of newbornsA 146 (17) 883 (3)
Maternal outcomes
 PPH requiring blood transfusionAC 36 (4) 607 (2) 10 (3) 403 (3) 175 (3) 3389 (2)
 Mother’s length of stay (median (IQR) in days)A 6 (4–8) 3 (2–5)
  1. SD standard deviation, IQR Interquartile range. 1The superscripts ABCDabcd which appear next to the demographic factors indicate whether two groups were statistically significantly different: A or a for a comparison of WA Aboriginal singletons and twins; B or b for a comparison of NSW Aboriginal singletons and twins; C or c for a comparison of NSW non-Aboriginal singletons and twins; and D or d for a comparison of NSW Aboriginal twins and NSW non-Aboriginal twins. Pearson’s chi-squared tests were conducted for all variables except length of stay. Wilcoxon rank sum tests were conducted for infant and maternal length of stay. A capital letter indicates p < 0.001 and a lower-case letter indicates a 0.001 < p < 0.05. 2In WA, admission to a NICU or SCN in the hospital the infant was born in and admission to a NICU in any hospital they were transferred to were included (time in a SCN after being transferred to another hospital was not available). In NSW, admission to a NICU or SCN in the hospital the infant was born in was included (admission to a NICU or SCN after transfer was not available). Data were missing for: birth weight (0 infants in WA, 286 in NSW), gestational age (45 infants in WA, 433 in NSW), resuscitation (0 infants in WA, 932 in NSW), admitted to NICU or SCN (18,122 infants in WA, 581 in NSW), PPH requiring blood transfusion (0 infants in WA, 401967 in NSW) and mother’s length of stay (90 cases in WA). No data were missing for stillbirth, neonatal death, infant length of stay, cerebral palsy or respiratory distress syndrome of newborns