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Table 1 Distribution of background characteristics by pregnancy outcome

From: Pre-pregnancy lifestyle characteristics and risk of miscarriage: the Australian Longitudinal Study on Women’s Health

  Live or stillbirth
(N = 18,186)
Miscarriage
(N = 5317)
Induced abortion
(N = 3089)
P-value
Age, Mean(SD) 27.9 (5.6) 28.5 (6.4) 25.5 (6.3) < 0.001
Marital status, N(%)     < 0.001
 Married or de facto 13,969 (76.8) 3678 (69.2) 1390 (45.0)  
 Other 4139 (22.8) 1620 (30.5) 1687 (55.0)  
 Missing 78 (0.4) 19 (0.4) 12 (0.4)  
Area of residence, N(%)     0.002
 Major cities 9560 (52.6) 2892 (54.4) 1687 (54.6)  
 Inner regional 4982 (27.4) 1471 (27.7) 857 (27.7)  
 Outer regional 2759 (15.2) 741 (13.9) 404 (13.1)  
 Remote/very remote 604 (3.3) 139 (2.6) 102 (3.3)  
 Missing 281 (1.5) 74 (1.4) 39 (1.3)  
Managing on income, N(%)     < 0.001
 Impossible 352 (1.9) 127 (2.4) 95 (3.1)  
 Difficult always 2118 (11.6) 656 (12.3) 525 (17.0)  
 Difficult sometimes 5543 (30.5) 1478 (27.8) 964 (31.2)  
 Not too bad 6246 (34.4) 1783 (33.5) 867 (28.1)  
 It is easy 2364 (13.0) 749 (14.1) 350 (11.3)  
 Missing 1563 (8.6) 624 (11.7) 288 (9.3)  
Educational level, N(%)     < 0.001
 Less than year 12 2111 (11.6) 598 (11.2) 478 (15.5)  
 Year 12 or equivalent 4191 (23.0) 1291 (24.3) 1127 (36.5)  
 Certificate/diploma 4204 (23.1) 1254 (23.6) 680 (22.0)  
 University 7441 (40.9) 2117 (39.8) 754 (24.4)  
 Missing 239 (1.3) 57 (1.1) 50 (1.6)  
Occupation, N(%)     < 0.001
 Manager/professional 8022 (44.1) 2436 (45.8) 1283 (41.5)  
 Semi skilled 5538 (30.5) 1619 (30.4) 1100 (35.6)  
 Unskilled 1143 (6.3) 338 (6.4) 230 (7.4)  
 Not in labour force 3115 (17.1) 817 (15.4) 408 (13.2)  
 Missing 368 (2.0) 207 (3.9) 68 (2.2)  
Number of previous pregnancies, N(%)     < 0.001
 0 7100 (39.0) 1018 (19.1) 1095 (35.4)  
 1 5748 (31.6) 1314 (24.7) 639 (20.7)  
 2+ 5338 (29.4) 2985 (56.1) 1355 (43.9)  
Smoking status, N(%)     < 0.001
 Never smoker 10,190 (56.0) 2716 (51.1) 1159 (37.5)  
 Former smoking 4349 (23.9) 1315 (24.7) 679 (22.0)  
 Less than 10 cigarettes per day 1332 (7.3) 428 (8.0) 411 (13.3)  
 Between 10 and 19 cigarettes per day 989 (5.4) 381 (7.2) 332 (10.7)  
 20 or more cigarettes per day 626 (3.4) 234 (4.4) 223 (7.2)  
 Current smoker but unknown number of cigarettes per day 445 (2.4) 157 (3.0) 189 (6.1)  
 Missing 255 (1.4) 86 (1.6) 96 (3.1)  
Body-mass index, N(%)     < 0.001
 Underweight 751 (4.1) 246 (4.3) 172 (5.6)  
 Normal weight 9602 (52.8) 2772 (52.1) 1731 (56.0)  
 Overweight 3534 (19.4) 1120 (21.1) 533 (17.3)  
 Obese 2045 (11.2) 794 (14.9) 316 (10.2)  
 Missing 2254 (12.4) 385 (7.2) 337 (10.9)  
Alcohol intake, N(%)     < 0.001
 Low risk drinker 15,307 (84.2) 4508 (84.8) 2634 (85.3)  
 Non-drinker 2172 (11.9) 509 (9.6) 196 (6.3)  
 Risky drinker 584 (3.2) 259 (4.9) 233 (7.5)  
 Missing 123 (0.7) 41 (0.8) 26 (0.8)