Those are not unrelated. Both from my family and from looking at the research, there's a strong correlation between long/difficult births (sometimes explicitly hypoxia) and autism.
Would you mind pointing me at the research you found? I've been looking for studies that correlated hypoxia and autism (and related interventions that might help) but I haven't been successful.
Not that long ago (in the last decade) I spoke to a researcher working to identify autism in the womb. Seems odd thing to chase if it’s caused by birth difficulties.