Complex sentence: A Caesarean section is usually performed when a vaginal delivery would put the baby's or mother's life or health at risk, although in recent times it has also been performed upon request for childbirths that could otherwise have been natural.
Split into simpler sentences: A Caesarean section is usually performed when a vaginal delivery would put the baby's or mother's life or health at risk. More recently it has been performed upon request for childbirths that may otherwise have been natural.