| Maternal age group | ||||||
---|---|---|---|---|---|---|---|
< 20 (N = 42) | 20–24 (N = 254) | 25–29 (N = 1105) | 30–34 (N = 2668) | 35–39 (N = 2972) | ≥40 (N = 911) | p-value | |
Year of birth | |||||||
 2007 | 3 (7.1) | 19 (7.5) | 96 (8.7) | 229 (8.6) | 197 (6.6) | 26 (2.9) | < 0.0001 |
 2008 | 3 (7.1) | 22 (8.7) | 106 (9.6) | 272 (10.2) | 235 (7.9) | 32 (3.5) |  |
 2009 | 4 (9.5) | 19 (7.5) | 89 (8.1) | 276 (10.3) | 279 (9.4) | 66 (7.24) |  |
 2010 | 3 (7.1) | 17 (6.7) | 92 (8.3) | 242 (9.1) | 271 (9.1) | 72 (7.9) |  |
 2011 | 6 (14.3) | 22 (8.7) | 126 (11.4) | 249 (9.3) | 297 (10.0) | 77 (8.45) |  |
 2012 | 1 (2.4) | 32 (12.6) | 108 (9.8) | 230 (8.6) | 270 (9.1) | 97 (8.5) |  |
 2013 | 6 (14.3) | 20 (7.9) | 121 (11.0) | 270 (10.1) | 298 (10.0) | 95 (10.4) |  |
 2014 | 5 (11.9) | 31 (12.2) | 99 (9.0) | 257 (9.6) | 297 (10.0) | 131 (14.4) |  |
 2015 | 7 (16.7) | 23 (9.1) | 80 (7.2) | 202 (7.6) | 288 (9.7) | 114 (12.5) |  |
 2016 | 2 (4.8) | 28 (11.0) | 99 (9.0) | 220 (8.3) | 278 (9.4) | 109 (12.0) |  |
 2017 | 2 (4.8) | 21 (8.3) | 89 (8.1) | 221 (8.3) | 262 (8.8) | 92 (10.1) |  |
Maternal citizenship | |||||||
 Italian | 28 (66.7) | 171 (67.3) | 862 (78.0) | 2265 (84.9) | 2610 (87.8) | 820 (90.0) | < 0.0001 |
 Not Italian | 14 (33.3) | 83 (32.7) | 243 (22.0) | 403 (15.1) | 362 (12.2) | 91 (10.0) |  |
Marital status a | |||||||
 Married | 7 (17.1) | 110 (44.00) | 712 (66.1) | 1991 (76.8) | 2134 (73.3) | 560 (63.0) | < 0.0001 |
 Not married | 34 (82.9) | 140 (56.00) | 366 (33.9) | 600 (23.2) | 776 (26.7) | 329 (37.0) |  |
Maternal education b | |||||||
 Middle school | 32 (78.1) | 123 (48.4) | 368 (33.4) | 528 (19.9) | 545 (18.4) | 145 (15.9) | < 0.0001 |
 High school | 8 (19.5) | 116 (45.7) | 531 (48.2) | 1218 (45.8) | 1237 (41.7) | 387 (42.5) |  |
 University | 1 (2.5) | 15 (5.9) | 202 (18.4) | 912 (34.3) | 1183 (39.9) | 378 (41.5) |  |
Maternal employment | |||||||
 Employed | 4 (9.5) | 102 (40.2) | 790 (71.5) | 2143 (80.3) | 2470 (83.1) | 782 (85.8) | < 0.0001 |
 Not employed | 38 (90.5) | 152 (59.8) | 315 (28.5) | 525 (19.7) | 502 (16.9) | 129 (14.2) |  |
Mode of conception | |||||||
 Spontaneous | 42 (100.0) | 246 (96.9) | 963 (87.2) | 2061 (77.3) | 1958 (65.9) | 333 (36.6) | < 0.0001 |
 Non spontaneous | 0 (0.0) | 8 (3.1) | 142 (12.8) | 607 (2.7) | 1014 (34.1) | 578 (63.5) |  |
Diabetes | |||||||
 No | 42 (100.0) | 253 (99.6) | 1099 (99.5) | 2637 (98.8) | 2938 (98.9) | 899 (98.7) | 0.3693 |
 Yes | 0 (0.0) | 1 (0.4) | 6 (0.5) | 31 (1.2) | 34 (1.1) | 12 (1.3) |  |
Hypertension | |||||||
 No | 38 (90.5) | 250 (98.4) | 1072 (97.0) | 2601 (97.5) | 2893 (97.3) | 870 (95.5) | 0.0022 |
 Yes | 4 (9.5) | 4 (1.6) | 33 (3.0) | 67 (2.5) | 79 (2.7) | 41 (4.5) |  |