Intellectual Disability in ASD. Paternal and Obstetric Factors in Relation with Cognitive LEVEL Outcome

Background: Different environmental and family factors have been associated with increased risk of Autism Spectrum Disorders (ASD) and/or its severity. Among these, advanced parental age (APA) is associated with increased risk of ASD [Janecka et al 2017; McGrath et al 2014] and one of the mechanisms proposed is that autistic traits in the parents may lead to delay age at conception [Gratten et al 2016]. Perinatal factors such as the use of oxytocin in labour have been associated with the severity of ASD [Smallwood 2016].

Objectives: In this presentation we aim to report on the effect of some parental and perinatal factors on the severity of ASD, as indicated by cognitive development [8].

Methods: Eighty patients with ASD ( DSM-IV-TR diagnosis), mean age 13.25 ±7.7SD, 87.5% male, 92.5% Caucasian) were recruited at Hospital General Universitario Gregorio Marañón. Intelligence quotient (IQ) was assessed with the Wechsler Intelligence Scales for Children or Adults, as appropriate. Parental autism traits were evaluated with the Autism Spectrum Quotient (AQ). The presence of obstetric complications was evaluated with the Lewis-Murray Obstetric Complications Scale. After confirming the normality of data, Pearson correlation analyses were used to assess the relationship between parental autism traits and age at conception, and between and multiple linear regression were used to assess the potential association of patients IQ with the parental (APA, psychiatric history and autism traits), and obstetric predictors (birthweight, obstetric complications or labour oxytocin use). Statistical analyses were performed with SPSS 18. Statistically significance threshold p<0.05.

Results: 66.3% of the sample had fluent language and 31.3% only words/simple phrases (as per ADOS criteria). Mothers aged from 23 to 41 years old, mean age 31.99 SD=4.072 and fathers aged from 22 to 47, mean age 34.23 SD=5.31. 23.75% of parents had a positive psychiatric history. ASD birthweight was 3260.5±497.04SD [1950-4300] g; 62.5% of the cases had a positive history of obstetric complications.

Fathers of ASD probands had a mean AQ of 16.6 ±6 and mothers had a mean AQ of 14.8 ±6.7. Paternal or maternal autistic traits did not correlate with their age at ASD birth (r=.209, p=.145 and r=.035, p=.798 respectively). The use of oxytocin during labour was significantly associated with proband IQ (IQ mean 84.251 ±25SD [40-133], association with oxytocin use t=2469, p=.016). With regard to associations among risk variables, the presence of obstetric complications significantly correlated with birthweight (t=2.155, s=.034), maternal age at birth (t=-2.256, s=.027) and parental autism traits (t=-2.004, s=.051). Labour oxytocin was associated with the presence of ASD diagnosis before 1 year of age (s=.010). Multiple regression analysis showed that oxytocin use predicts IQ (B=-13.673, s=.016) , after controlling for age, sex and ethnicity (R2=.073).

Conclusions: Labour oxytocin use does partially predict IQ in ASD patients. Contrary to our hypothesis, parental autism traits does not predict IQ outcome. The direction of the relationship oxytocin use-IQ in ASD patients is, hitherto, unknown and needs further investigation.