Table 6.
Crude and Adjusted Odds Ratios (ORadj) and 95% Confidence Intervals (CIs) for Autism Spectrum Disorders (ASDs) Associated with Maternal Infections Diagnosed during an Inpatient Hospitalization, Kaiser Permanente Northern California Childhood Autism Perinatal Study, 1995 – 1999
| Exposure | ASD Cases (N = 407) n(%) |
Controls (N=2075) n (%) |
Crude OR (95% CI) | OR adj* (95% CI) |
|---|---|---|---|---|
| Unexposed group** | 199 (48.9) | 1080 (52.0) | reference | reference |
| Any infection | ||||
| Pregnancy period1 | 64 (15.7) | 249 (12.0) | 1.39 (1.02 – 1.91) | 1.48 (1.07 – 2.04) |
| 1st Trimester | 2 (0.5) | 1 (0.0) | - | - |
| 2nd Trimester | 6 (1.5) | 11 (0.5) | 2.96 (1.08 – 8.10) | 3.80 (1.31 – 11.08) |
| 3rd Trimester | 59 (14.5) | 242 (11.7) | 1.32 (0.96 – 1.83) | 1.39 (1.0 – 1.94) |
| Bacterial Infection | ||||
| Pregnancy period1 | 38 (9.3) | 150 (7.2) | 1.38 (0.93 – 2.03) | 1.58 (1.06 – 2.37) |
| 1st Trimester | 0 | 1 | - | - |
| 2nd Trimester | 4 (0.9) | 8 (0.4) | - | - |
| 3rd Trimester | 35 (8.6) | 144 (6.9) | 1.32 (0.89 – 1.97) | 1.50 (1.00 – 2.27) |
*
All ORs were adjusted for the matching variables (child sex, year of birth and hospital of birth) in addition to maternal age and race/ethnicity.
**
The unexposed group had no diagnosed infections during the period from 30 days before pregnancy to delivery.
1
The pregnancy period is defined as the time between the LMP and the date of delivery.