Table 1 Unadjusted characteristics of the study population (n = 708,475) stratified maternal region of origin
Region of Origin | Australia | Americas | Europe | North East, North Africa, Middle East | Oceania, Antarctica | South East Asia | Southern, Central Asia | Sub-Saharan Africa | Â |
|---|---|---|---|---|---|---|---|---|---|
|  | n = 461,903 (65.2%) | n = 9616 (1.4%) | n = 34,533 (7.9%) | n = 55,737 (7.9%) | n = 20,046 (2.8%) | n = 44,943 (6.3%) | n = 66,883 (9.4%) | n = 14,814 (2.1%) |  |
Demographics | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | p value |
Birthweight | |||||||||
  < 10th Centile | 33,749 (7.3) | 769 (8.0) | 2397 (6.9) | 5563 (10.0) | 1399 (7.0) | 5485 (12.1) | 10,705 (16.0) | 1524 (10.3) | <  0.001 |
  > 10th Centile | 428,154 (92.7) | 8847 (92.0) | 32,136 (93.1) | 50,174 (90.0) | 18,647 (93.0) | 39,485 (87.9) | 56,178 (84.0) | 13,290 (89.7) | |
Sex - Baby | |||||||||
 Male | 235,529 (51.0) | 4821 (50.1) | 17,646 (51.1) | 28,648 (51.4) | 10,264 (51.2) | 23,044 (51.3) | 34,307 (51.3) | 7504 (50.7) | = 0.179 |
 Female | 226,374 (49.0) | 4795 (49.9) | 16,887 (48.9) | 27,089 (48.6) | 9782 (48.8) | 21,899 (48.7) | 32,576 (48.7) | 7310 (49.3) | |
Gestational Age Grouped | |||||||||
 Preterm < 37 weeks | 63,312 (13.7) | 1186 (12.3) | 4065 (11.8) | 6334 (11.4) | 2686 (13.4) | 6665 (14.8) | 10,117 (15.1) | 1849 (12.5) | <  0.001 |
 Term ≥37 weeks | 398,591 (86.3) | 8430 (87.7) | 30,468 (88.2) | 49,403 (88.6) | 17,360 (86.6) | 38,278 (85.2) | 56,766 (84.9) | 12,965 (87.5) | |
Relationship Status | |||||||||
 In a Relationship | 388,233 (85.4) | 8988 (94.4) | 32,154 (94.0) | 51,882 (93.7) | 16,440 (82.9) | 40,559 (90.9) | 65,873 (98.8) | 12,639 (85.9) | <  0.001 |
 Not in a relationship | 66,453 (14.6) | 538 (5.6) | 2039 (6.0) | 3492 (6.3) | 3400 (17.1) | 4048 (9.1) | 810 (1.2) | 2077 (14.1) | |
Maternal Age Grouped | |||||||||
  <  20 | 11,703 (2.5) | 32 (0.3) | 124 (0.4) | 503 (0.9) | 559 (2.8) | 285 (0.6) | 156 (0.2) | 192 (1.3) | <  0.001 |
 20–35 | 358,684 (77.7) | 6822 (71.0) | 24,206 (70.1) | 44,953 (80.7) | 15,223 (76.0) | 34,707 (77.2) | 60,138 (89.9) | 11,368 (76.7) | |
 35+ | 91,311 (19.8) | 2757 (28.7) | 10,187 (29.5) | 10,274 (18.4) | 4257 (21.2) | 9945 (22.1) | 6579 (9.8) | 3252 (22.0) | |
Parity | |||||||||
 Multiparous | 263,087 (57.0) | 5057 (52.6) | 18,783 (54.4) | 30,998 (55.6) | 12,692 (63.3) | 25,237 (56.2) | 32,205 (48.2) | 9767 (66.0) | <  0.001 |
 Nulliparous | 198,771 (43.0) | 4557 (47.4) | 15,745 (45.6) | 24,734 (44.4) | 7349 (36.7) | 19,701 (43.8) | 34,670 (51.8) | 5041 (34.0) | |
Maternal SEIFA | |||||||||
 Advantage | 179,694 (41.6) | 4863 (53.4) | 17,377 (53.1) | 20,896 (39.3) | 6616 (34.8) | 13,599 (31.6) | 18,465 (29.2) | 4774 (33.9) | <  0.001 |
 Average | 89,356 (20.7) | 1703 (18.7) | 6218 (19.0) | 9766 (18.3) | 3741 (19.7) | 6938 (16.1) | 13,194 (20.8) | 2115 (15.0) | |
 Disadvantage | 162,815 (37.7) | 2541 (27.9) | 9144 (27.9) | 22,571 (42.4) | 8679 (45.6) | 22,511 (52.3) | 31,651 (50.0) | 7189 (51.1) | |
Maternal Health and Health Behaviours | |||||||||
 Body Mass Index | |||||||||
   < 18.5 | 12,653 (2.9) | 259 (2.9) | 905 (2.8) | 1663 (3.2) | 520 (2.8) | 1434 (3.4) | 2242 (3.6) | 416 (3.1) | <  0.001 |
  18.5–24.99 | 215,510 (50.2) | 4521 (51.1) | 15,999 (50.2) | 26,570 (51.6) | 9257 (49.5) | 21,814 (52.3) | 32,425 (52.1) | 6891 (51.0) | |
   > 25 | 201,141 (46.9) | 4071 (46.0) | 14,972 (47.0) | 23,278 (45.2) | 8919 (47.7) | 18,435 (44.2) | 27,541 (44.3) | 6211 (45.9) | |
 Smoking before 20wks | |||||||||
  Smoker | 60,786 (13.4) | 366 (3.9) | 2469 (7.2) | 1490 (2.7) | 3296 (16.8) | 968 (2.2) | 285 (0.4) | 445 (3.0) | <  0.001 |
  Non-Smoker | 393,058 (86.6) | 9136 (96.1) | 31,648 (92.8) | 53,622 (97.3) | 16,288 (83.2) | 43,615 (97.8) | 66,384 (99.6) | 14,251 (97.0) | |
 Smoking after 20wks | |||||||||
  Smoker | 32,872 (8.5) | 114 (1.3) | 951 (3.2) | 613 (1.2) | 1873 (10.8) | 323 (0.8) | 77 (0.1) | 173 (1.3) | <  0.001 |
  Non-Smoker | 352,354 (91.5) | 8413 (98.7) | 28,943 (96.8) | 50,486 (98.8) | 15,421 (89.2) | 40,277 (99.2) | 61,892 (99.9) | 13,060 (98.7) | |
 Gestational Age 1st visit | |||||||||
  Before 11 weeks | 222,760 (48.8) | 4391 (46.2) | 15,280 (44.7) | 21,824 (39.5) | 6328 (32.0) | 16,386 (36.8) | 22,453 (33.8) | 4786 (32.7) | <  0.001 |
  12 to 23 weeks | 202,110 (44.2) | 4471 (47.0) | 16,817 (49.2) | 28,276 (51.2) | 10,039 (50.7) | 24,050 (54.0) | 38,399 (57.8) | 8210 (56.2) | |
  After 23 weeks/no care | 31,976 (7.0) | 644 (6.8) | 2098 (6.1) | 5139 (9.3) | 3427 (17.3) | 4113 (9.2) | 5621 (8.5) | 1691 (11.1) | |
Maternal Medical and Pregnancy Complications | |||||||||
 Type 1 Diabetes | |||||||||
  Yes | 1863 (0.4) | 18 (0.2) | 85 (0.2) | 90 (0.2) | 82 (0.4) | 97 (0.2) | 303 (0.5) | 51 (0.3) | <  0.001 |
  No | 460,040 (99.6) | 9598 (99.8) | 34,448 (99.8) | 55,647 (99.8) | 19,964 (99.6) | 44,846 (99.8) | 66,580 (99.5) | 14,763 (99.7) | |
 Type 2 Diabetes | |||||||||
  Yes | 717 (0.2) | 21 (0.2) | 38 (0.1) | 150 (0.3) | 103 (0.5) | 162 (0.4) | 386 (0.6) | 88 (0.6) | <  0.001 |
  No | 461,186 (99.8) | 9595 (99.8) | 34,495 (99.9) | 55,587 (99.7) | 19,943 (99.5) | 44,781 (99.6) | 66,497 (99.4) | 14,726 (99.4) | |
 Pre-existing Hypertension | |||||||||
  Yes | 6039 (1.3) | 117 (1.2) | 333 (1.0) | 344 (0.6) | 256 (1.3) | 449 (1.0) | 539 (0.8) | 174 (1.2) | <  0.001 |
  No | 455,864 (98.7) | 9499 (98.8) | 34,200 (99.0) | 55,393 (99.4) | 19,790 (98.7) | 44,494 (99.0) | 66,344 (99.2) | 14,640 (98.8) | |
 Gestational Diabetes -Diet | |||||||||
  Yes | 18,506 (4.0) | 467 (4.9) | 1668 (4.8) | 5379 (9.7) | 1191 (5.9) | 5283 (11.8) | 8399 (12.6) | 1046 (7.1) | <  0.001 |
  No | 443,397 (96.0) | 9149 (95.1) | 32,865 (95.2) | 50,358 (90.3) | 18,855 (94.1) | 39,660 (88.2) | 58,484 (87.4) | 13,768 (92.9) | |
 Gestational Diabetes - Insulin | |||||||||
  Yes | 12,769 (2.8) | 315 (3.3) | 974 (2.8) | 2835 (5.1) | 889 (4.4) | 2503 (5.6) | 6663 (10.0) | 740 (5.0) | <  0.001 |
  No | 449,134 (97.2) | 9301 (96.7) | 33,559 (97.2) | 52,902 (94.9) | 19,157 (95.6) | 42,440 (94.4) | 60,220 (90.0) | 14,074 (95.0) | |
 Pre-Eclampsia | |||||||||
  Yes | 10,332 (2.2) | 144 (1.5) | 582 (1.7) | 590 (1.1) | 510 (2.5) | 697 (1.6) | 1205 (1.8) | 309 (2.1) | <  0.001 |
  No | 451,571 (97.8) | 9472 (98.5) | 33,951 (98.3) | 55,146 (98.9) | 19,536 (97.5) | 44,246 (98.4) | 65,678 (98.2) | 14,505 (97.9) | |
 HELLP Syndrome | |||||||||
  Yes | 732 (0.2) | 13 (0.1) | 56 (0.2) | 58 (0.1) | 37 (0.2) | 59 (0.1) | 108 (0.2) | 47 (0.3) | <  0.001 |
  No | 461,171 (99.8) | 9603 (99.9) | 34,477 (99.8) | 55,679 (99.9) | 20,009 (99.8) | 44,844 (99.9) | 66,775 (99.8) | 14,767 (99.7) | |
 Suspected Fetal Growth Restriction | |||||||||
  Yes | 19,766 (4.3) | 370 (3.8) | 1276 (3.7) | 3156 (5.7) | 784 (3.9) | 2564 (5.7) | 5454 (8.2) | 681 (4.6) | <  0.001 |
  No | 442,137 (95.7) | 9246 (96.2) | 33,257 (96.3) | 52,581 (94.3) | 19,262 (96.1) | 42,397 (94.3) | 61,429 (91.8) | 14,133 (95.4) | |