Table 1.
Covariates in relation to maternal T. gondii IgM and IgG seropositivity and diagnostic classification (childhood autism, controls)
| IgM for Controls (n=874) | IgG for Controls (n=874) | Diagnostic Classification | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Covariates | Seronegative n (%) |
Seropositive n (%) |
X2/t | P | Seronegative n (%) |
Seropositive n (%) |
X2/t | P | Cases (n=874) n (%) |
Controls (n=874) n (%) |
X2/t | P |
| Maternal age | 0.02 | 0.89 | 12.29 | 0.0005 | 8.72 | 0.003 | ||||||
| < Median (29.00) | 391 (45.78) | 9 (45.00) | 331 (48.96) | 69 (34.85) | 339 (38.79) | 400 (45.77) | ||||||
| ≥Median | 463 (54.22) | 11 (55.00) | 345 (51.04) | 129 (65.15) | 535 (61.21) | 474 (54.23) | ||||||
| Paternal age | 0.12 | 0.73 | 8.07 | 0.005 | 6.55 | 0.01 | ||||||
| < Median (31.00) | 394 (46.14) | 10 (50.00) | 330 (48.82) | 74 (37.37) | 351 (40.16) | 404 (46.22) | ||||||
| ≥Median | 460 (53.86) | 10 (50.00) | 346 (51.18) | 124 (62.63) | 523 (59.84) | 470 (53.78) | ||||||
| Previous births (≥ 1) | 494 (57.85) | 12 (60.00) | 0.04 | 0.84 | 371 (54.88) | 135 (68.18) | 11.11 | 0.0009 | 581 (66.48) | 506 (57.89) | 13.68 | 0.0002 |
| Gestational Age (< 37 weeks) | 42 (4.92) | 2 (10.00) | 1.06 | 0.30 | 33 (4.88) | 11 (5.56) | 0.15 | 0.70 | 54 (6.18) | 44 (5.03) | 1.08 | 0.30 |
| Birth weight (< 2500 grams) | 22 (2.58) | 1 (5.00) | 0.45 | 0.50 | 18 (2.66) | 5 (2.53) | 0.01 | 0.92 | 39 (4.46) | 23 (2.63) | 4.28 | 0.04 |
| Maternal SESa | 2.00 | 0.57 | 0.76 | 0.86 | 1.43 | 0.70 | ||||||
| Upper white collar | 109 (15.87) | 2 (12.50) | 92 (16.25) | 19 (13.87) | 98 (13.59) | 111 (15.79) | ||||||
| Lower white collar | 311 (45.27) | 5 (31.25) | 254 (44.88) | 62 (45.26 | 331 (45.91) | 316 (44.95) | ||||||
| Blue collar | 146 (21.25) | 5 (31.25) | 122 (21.55) | 29 (21.17) | 157 (21.78) | 151 (21.48) | ||||||
| Others | 121 (17.61) | 4 (25.00) | 98 (17.31) | 27 (19.71) | 135 (18.72) | 125 (17.78) | ||||||
| Sex | 0.03 | 0.86 | 0.39 | 0.53 | --- | --- | ||||||
| Male | 669 (78.34) | 16 (80.00) | 533 (78.85) | 152 (76.77) | 685 (78.38) | 685 (78.38) | ||||||
| Female | 185 (21.66) | 4 (20.00) | 143 (21.15) | 46 (23.23) | 189 (21.62) | 189 (21.62) | ||||||
| Gestational week of blood drawb | 1.72 | 0.19 | 0.05 | 0.82 | 0.63 | 0.43 | ||||||
| < Median (10.00) | 321 (39.48) | 5 (25.00) | 253 (39.35) | 73 (38.42) | 308 (37.24) | 326 (39.14) | ||||||
| ≥Median | 492 (60.52) | 15 (75.00) | 390 (60.65) | 117 (61.58) | 519 (62.76) | 507 (60.86) | ||||||
Abbreviations: IgM, immunoglobulin M; SES, Socioeconomic Status;
a
frequency missing = 153 cases, 171 controls;
b
frequency missing = 47 cases, 41 controls.