Table 1.
Covariates in relation to maternal SES in controls and in relation to risk of ASD
| Relationship between covariates and maternal SES | Relationship between covariates and ASD | |||||
|---|---|---|---|---|---|---|
|
| ||||||
| Upper white collar workers, n (%) | Lower white collar workers, n (%) | Blue collar workers, n (%) | Others, n (%) | p-value* | p-value* | |
| Maternal age | <0.001 | <0.001 | ||||
| 14–24 | 44 (1.9) | 714 (11.3) | 678 (23.8) | 757 (31.0) | ||
| 25–39 | 2112 (93.2) | 5385 (85.3) | 2089 (73.4) | 1610 (65.9) | ||
| 40– | 11 (4.9) | 212 (3.4) | 81 (2.8) | 75 (3.1) | ||
| Paternal age$ | <0.001 | <0.001 | ||||
| 15–24 | 46 (2.0) | 406 (6.4) | 349 (12.3) | 419 (17.2) | ||
| 25–39 | 1905 (84.0) | 5272 (83.5) | 2245 (78.8) | 1801 (73.8) | ||
| 40– | 316 (13.9) | 633 (10.0) | 254 (8.9) | 222 (9.1) | ||
| Parental psychiatric disorder or intellectual disability | 156 (6.9) | 631 (10.0) | 450 (15.8) | 380 (15.6) | <0.001 | <0.001 |
| Maternal smoking% | 117 (5.2) | 836 (13.5) | 759 (27.2) | 452 (18.8) | <0.001 | 0.030 |
| Parity (≥2 births)§ | 458 (20.2) | 1474 (23.4) | 711 (25.0) | 864 (35.4) | <0.001 | <0.001 |
| Weight for gestational age–,’ | 0.039 | <0.001 | ||||
| SGA | 28 (1.2) | 118 (1.9) | 62 (2.2) | 46 (1.9) | ||
| AGA | 2177 (96.2) | 5973 (94.8) | 2678 (94.2) | 2298 (94.4) | ||
| LGA | 57 (2.5) | 207 (3.3) | 102 (3.6) | 91 (3.7) | ||
*
X2 test.
$
Frequency missing = 84 cases, 163 controls.
%
Frequency missing = 117 cases, 352 controls.
§
Frequency missing = 16 cases, 60 controls.
–
Frequency missing = 26 cases, 82 controls.
’
SGA = small for gestational age, AGA = appropriate for gestational age, LGA = large for gestational age