"accident of birth" and "delivered ... by caesarian section"

[Odessa Dawn]

A few miles away across Bo District at the Gondama referral centre run by Médecins Sans Frontières (Doctors Without Borders), obstetrician Dr Phillip de Almeida weeps into his hands. He has just delivered a stillborn child by caesarian section, and he knows the baby’s mother, Cadeta, has little chance of surviving the night.

Things are little better for 36-year-old Neang, a pregnant mother from rural Cambodia with HIV. By pure geographical accident of birth, her children are more likely to grow up malnourished than attend high school.

More: Four Born Every Second: Documentary chronicles four births in extreme poverty - Features - TV & Radio - The Independent
Are the underlined parts antonyms? I need an antonym for "delivered by caesarian section."

[5jj]

They are not anything like antonyms.There is no antonym as such for delivery by caesarian birth.

'By pure geographical accident of birth' the writer simply means 'by the mere chance of being born where they happened to be born'.

[Odessa Dawn]

I do mean that when a female delivers naturally without caesarian birth. What do we call that?

[5jj]

Natural birth or natural/vaginal delivery.