Table 3.
Crude and Adjusted Odds Ratios (ORadj) and 95% Confidence Intervals (CIs) for Autism Spectrum Disorders (ASD) Associated with Any Maternal Infection, Kaiser Permanente Northern California Childhood Autism Perinatal Study, 1995 – 1999
| Exposure* | ASD Cases (N= 407) n (%) |
Controls (N= 2075) n (%) |
Crude OR (95%) | ORadj ** (95% CI) |
|---|---|---|---|---|
| Unexposed group*** | 199 (48.9) | 1080 (52.0) | reference | reference |
| Any infection | ||||
| 30 Days Pre Conception | 33 (8.1) | 124 (6.0) | 1.44 (0.96 – 2.18) | 1.41 (0.92 – 2.18) |
| Pregnancy period1 | 198 (49.0) | 960 (46.3) | 1.12 (0.90 – 1.39) | 1.15 (0.92 – 1.43) |
| 1st Trimester | 75 (18.4) | 408 (19.7) | 1.00 (0.75 – 1.33) | 1.07 (0.79 – 1.45) |
| 2nd Trimester | 81 (19.9) | 369 (17.8) | 1.19 (0.90 – 1.58) | 1.21 (0.90 – 1.63) |
| 3rd Trimester | 109 (26.8) | 512 (24.7) | 1.15 (0.89 – 1.49) | 1.17 (0.90 – 1.52) |
| 3rd Trimester minus Delivery Day | 72 (17.7) | 326 (15.7) | 1.20 (0.89 – 1.60) | 1.16 (0.86 – 1.58) |
*
Maternal infections diagnosed during an inpatient hospitalization or outpatient clinic visit during pregnancy.
**
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 last menstrual period date and the date of delivery.