Older parents
Choice of partners so more selection on interests and intelligence or workplaces
Possibly diet and weight. As pcos and diabetes increases
Birth injuries and children surviving prematurity
Medication in pregnancy like that particular one for epilepsy
Logically if a person is a bit quirky and struggles socially their choice of partner maybe reduced.
People did used to have kids late but .. Obviously had kids from say 18/21 upwards so 2 kids in 40s but other 6+ kids born to younger.
Now having 2 kids but to older parents.
So imagine if say lead in water had an impact well a lot more built up by my 35th year than of i had dc at 21.
Working and commuting can be stressful and most do that during pregnancy.
Older dads is more mh issues in dc.
Also sub issue previously people lived close to relatives who would come over or drop in have a chat look after dc. Pre covid my parents visited ever 2 weeks or so. Diff conversation different people.
Is there higher instance of back to back births who are asd? Or breech?
As i think my side only has 2/8 who was neither (but1 was beech until 38 weeks)
Likewise another family of 2 dc had 1 with chord around neck and other born prem wth minor brain injury.
My school friends married and had a dc at 25yo who is asd. The dad was clever over chatty and quirky. I suspect his mum may have been autistic as there were MH issues.
Obviously blood glucose control and thyroid issues get worse as women get older.
As do autoimmune issues.
Im not convinced adhd is increasing. It maybe more that children with control issues actually stand out more as generally most children dont hit etc.
Some issues are being worsened or induced by schools and their attitudes. (And less supervision)