Table 1.
Covariates in relation to maternal early gestational C-reactive protein (CRP) levels in controls and in relation to risk of childhood autism.
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|---|---|---|---|---|---|
| CRP | Relationship between covariates and childhood autism | ||||
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| Covariates1 | ≥median | <median | X2/t | p | p |
| Maternal age (mean, SD) | 29.8 (5.3) | 29.6 (5.4) | −0.63 | 0.53 | 0.002 |
| Paternal age (mean, SD) | 32.5 (6.4) | 32.2 (6.3) | −0.81 | 0.42 | 0.005 |
| Previous births [N (%)≥2] | 102 (58.9) | 71 (41.0) | 7.34 | 0.007 | 0.35 |
| Maternal socioeconomic status2 | |||||
| Upper white collar [N (%)] | 40 (43.5) | 52 (56.5) | 9.91 | 0.02 | 0.74 |
| Lower white collar [N (%)] | 135 (53.2) | 119 (46.9) | |||
| Blue collar [N (%)] | 72 (61.5) | 45 (38.5) | |||
| Other [N (%)] | 44 (43.5) | 57 (56.4) | |||
| Pre-term birth ([N (%)]<37 weeks) | 13 (40.6) | 19 (59.3) | 1.19 | 0.27 | 0.19 |
| Low birthweight ([N (%)]<2500 g) | 10 (50.0) | 10 (50.1) | 0 | 0.99 | 0.09 |
| Family history [N (%) for each diagnostic category] | |||||
| Maternal SSD* | 3 (50) | 3 (50) | 0 | 0.99 | 0.15 |
| Parental SSD* | 4 (44.4) | 5 (55.6) | 0.12 | 0.73 | 0.03 |
| Maternal affective | 8 (57.1) | 6 (42.9) | 0.29 | 0.59 | 0.13 |
| Maternal depression | 6 (54.5) | 5 (45.5) | 0.09 | 0.76 | 0.10 |
| Parental affective | 13 (46.4) | 15 (53.6) | 0.15 | 0.69 | 0.03 |
| Maternal PDD** | 0 | 0 | -- | -- | 0.32 |
| Parental PDD** | 0 (0) | 1 (100) | 1.00 | 0.32 | 1.00 |
| Any maternal psychiatric disorder | 9 (50) | 9 (50) | 0 | 0.99 | 0.04 |
| Any parental psychiatric disorder | 28 (43.7) | 36 (56.2) | 1.13 | 0.29 | 0.11 |
| Gestational week of blood draw (mean, SD)3 | 11.4 (3.5) | 10.3 (3.3) | −5.62 | <0.001 | 0.53 |
*
SSD = Schizophrenia spectrum disorder;
**
PDD = Pervasive developmental disorder
1
There were no missing data on any covariates other than those noted in footnotes 2 and 3.
2
frequency missing = 91 cases, 113 controls;
3
frequency missing = 31 cases, 26 controls