Exposure to prenatal infection has been suggested to cause deficiencies in fetal neurodevelopment. In this study we included all children born in Denmark from 1980, through 2005. Diagnoses of autism spectrum disorders (ASDs) and maternal infection were obtained through nationwide registers. Data was analyzed using Cox proportional hazards regression. No association was found between any maternal infection and diagnosis of ASDs in the child when looking at the total period of pregnancy: adjusted hazard ratio = 1.14 (CI: 0.96-1.34). However, admission to hospital due to maternal viral infection in the first trimester and maternal bacterial infection in the second trimester were found to be associated with diagnosis of ASDs in the offspring, adjusted hazard ratio = 2.98 (CI: 1.29-7.15) and adjusted hazard ratio = 1.42 (CI: 1.08-1.87), respectively. Our results support prior hypotheses concerning early prenatal viral infection increasing the risk of ASDs.

Research suggests that heredity and early fetal development play a causal role in autism. This case-control study explored the association between perinatal factors, parental psychiatric history, socioeconomic status, and risk of autism. The study was nested within a cohort of all children born in Denmark after 1972 and at risk of being diagnosed with autism until December 1999. Prospectively recorded data were obtained from nationwide registries in Denmark. Cases totaled 698 children with a diagnosis of autism; each case was individually matched by gender, birth year, and age to 25 controls. Analyses by conditional logistic regression produced risk ratios and 95% confidence intervals. Adjusted analyses showed that the risk of autism was associated with breech presentation (risk ratio (RR) = 1.63, 95% confidence interval (CI): 1.18, 2.26), low Apgar score at 5 minutes (RR = 1.89, 95% CI: 1.10, 3.27), gestational age at birth <35 weeks (RR = 2.45, 95% CI: 1.55, 3.86), and parental psychiatric history (schizophrenia-like psychosis: RR = 3.44, 95% CI: 1.48, 7.95; affective disorder: RR = 2.91, 95% CI: 1.65, 5.14). Analyses showed no statistically significant association between risk of autism and weight for gestational age, parity, number of antenatal visits, parental age, or socioeconomic status. Results suggest that prenatal environmental factors and parental psychopathology are associated with the risk of autism. These factors seem to act independently.

Associations regarding family history of type 1 diabetes and infantile autism and maternal history of rheumatoid arthritis and ASDs were confirmed from previous studies. A significant association between maternal history of celiac disease and ASDs was observed for the first time. The observed associations between familial autoimmunity and ASDs/infantile autism are probably attributable to a combination of a common genetic background and a possible prenatal antibody exposure or alteration in fetal environment during pregnancy.

This study provides strong evidence against the hypothesis that MMR vaccination causes autism.

No abstract

Background-Inflammation mediated by cytokines may be important in the pathogenesis of bronchopulmonary dysplasia and the competing outcome of death in extremely low birth weight infants.

Despite evidence for the association of some pre-, peri- and neonatal risk factors associated with PDD, it remains unclear whether these risks are causal or play a secondary role in shaping clinical expression in individuals with genetic vulnerability. A plausible hypothsesis is that improvements in obstetric and neonatal management have led to an increased rate of survivors with pre-existing brain damage. Given the variety of risk factors, we propose that future studies should investigate combinations of multiple factors, rather than focusing on a single factor.

The purpose of this study was to assess the validity of the diagnosis of childhood autism in the Danish Psychiatric Central Register (DPCR) by reviewing medical records from 499 of 504 total children with childhood autism born 1990-1999. Based on review of abstracted behaviors recorded in case records from child psychiatric hospitals, case status determination was performed using a standardized coding scheme. In 499 children diagnosed with childhood autism in the DPCR, the diagnosis could be confirmed in 469 children (94%). Of the 30 non-confirmed cases, five were classified by the reviewers as non-autistic cases and the remaining 25 cases were either classified with another ASD diagnosis or the specific diagnosis was not possible to determine.