Purpose: Relative lengths of the index (2D) and ring (4D) fingers in humans represent a retrospective biomarker of prenatal hormonal exposures. For this reason, the 2D:4D digit ratio can be used to investigate potential hormonal contributions to the etiology of neurodevelopmental disorders. This study tested potential group differences in 2D:4D…

This study examined the differential contribution of pre-and perinatal risks in narrowly versus broadly defined autism spectrum disorder (ASD) and across core symptom domains, IQ and co-morbid problems. Children with a DSM-IV diagnosis of autistic disorder (AD) (n = 121) or pervasive developmental disorder not otherwise specified (PDD-NOS)…

Background: Inhibitory control (IC) has been regarded as a neuropsychological basic deficit and as an endophenotype of attention deficit/hyperactivity disorder (ADHD). Implicated here are mediation processes between etiological factors and ADHD symptoms. We thus analyze whether and to what extent executive IC and delay aversion (DA; i.e.,…

Aim: It has been suggested that high levels of prenatal testosterone exposure are implied in the aetiology of attention-deficit-hyperactivity disorder (ADHD). This study examined the association between the ratio of the length of the second and fourth digits (2D:4D ratio), a marker of fetal testosterone exposure, and the presence of ADHD-related…

The worldwide incidence of neural tube defects (NTDs) ranges from 1.0 to 10.0 per 1,000 births with almost equal frequencies between two major categories: anencephaly and spina bifida (SB). Epidemiological studies have provided valuable insight for (a) researchers to identify nongenetic and genetic factors contributing to etiology, (b) public…

Of particular interest to studying the etiology of Autistic Spectrum Disorders (ASDs) is the potential for multiple risk factors to combine through non-random mechanisms--assortative mating. Both genetic influences and a high-testosterone prenatal environment have been implicated in the etiology of ASDs, and given that waist-hip ratio (WHR) is…

Twenty-five autistic children were compared with 25 controls for number of factors identified as optimal in the pre-, peri-, and neonatal period, as noted in medical records. Autistic Ss showed greatly reduced optimality, especially with regard to prenatal factors, in contrast with other reports denying brain injury in autism. (Author/CL)

The article presents a case history of a pair of male monozygotic twins who both had autism. During pregnancy the mother suffered from severe toxemia, and delivery occurred 2 months before term. (Author/DLS)

Children (N=434) with nonsyndromic mental retardation were analysed for frequency of prenatal, perinatal and infantile biological disturbances. Mildly retarded individuals of unrelated parentage, both idiopathic and familial, had a strikingly higher prevalence of disturbances than a control group of retarded individuals with consanguineous parents…

Examination of 1,000 Finnish patients with mental retardation indicated that infectious diseases were the only cause of mental retardation in 11.1 percent and a contributory cause in a further 1.5 percent. Among the former group of 111 patients, the causative infectious disease operated prenatally in 18 percent and perinatally/postnatally in 82…

Pregnancy and delivery complications in the birth of 23 high-functioning autistic females and 23 high-functioning autistic males of similar intelligence quotient and age were compared with those of 54 normally developing siblings. Findings suggest that these factors may be less significant in high-functioning individuals than in severely retarded…

Birth order and maternal ages at time of birth were compared for 113 autistic children (3 to 12 years old) and the Iowa general population. An excess of mothers aged 35 or older was observed in the autistic group. A deviation from average in birth order was observed in autistics. (Author/SEW)

The first complex etiological study of mental retardation in Budapest was carried out with 1,364 children ages 7 to 14 years. Results are compared with findings from previous surveys in the United States and the United Kingdom. (Author)

This paper presents two case studies of children who developed herpes virus infection in the intrauterine or early postnatal period and presented with features of autism around two years of age. Other research suggesting a link between herpes and autism is reviewed. (DB)

Background: Prenatal problems are among theorized etiologies for child disruptive behavior problems. A key question concerns whether etiological contributors are shared across the broad range of disruptive psychopathology or are partially or largely distinct. Method: We examined prenatal smoking exposure and low birth weight as risk factors for…