Language deficit in boys with autism spectrum disorder in relation to maternal reproductive health, endocrine disruptors, and delivery method.

Objectives: The presented research aimed to identify prenatal factors involved in abnormal neurodevelopment and postnatal manifestation of an autistic phenotype in 107 boys (average age 4.31 ± 2.24 years).

Materials and methods: Their biological mothers were asked to fill out a comprehensive questionnaire about their reproductive health, infections during pregnancy, oral contraceptive intake before conception, and potential substance abuse before and during pregnancy as well as delivery and newborn information. The boys were subsequently diagnosed with autism spectrum disorder (ASD) using the combination of Autism Diagnostic Observation Schedule (ADOS-2) and Autism Diagnostic Interview - Revised (ADI-R). Based on the ADOS-2 module chosen during diagnosis, boys diagnosed with Module 1 can be classified as nonverbal or minimally verbal (N = 68), while those diagnosed using Module 3 are fully verbal (N = 39).

Results: According to our results, reproductive health related to the length of the menstrual cycle before pregnancy with the autistic child seems to play a role with regards to the severity of the disorder (P = 0.017) as well as the number of previous pregnancies (P = 0.026). Mothers of nonverbal children reported to have had a much shorter menstrual cycle (27.35 ± 6.60 days) than those with verbal children (30.14 ± 4.44 days) and reported more previous pregnancies (0.93 ± 1.07 vs. 0.51 ± 0.91), while not reporting the number of live births before they had the autistic child. Children who were later diagnosed as non-verbal had a longer delivery time (from 2 to 48 hours; on average 11.13 hours, SD = 9.49) than verbal ones (between 1 and 27 hours, which was on average 7.09 hours, SD = 8.91), P = 0.0182. Delivery method didn't play a role in this context, and neither did the type of conception (natural, insemination, etc.).

Conclusion: Studying the involvement of prenatal factors in the etiology of autism based on the speech of the child seems to be a promising approach.