https://www.theguardian.com/lifeandstyle/2022/feb/13/caesareans-or-vaginal-births-should-mothers-or-medics-have-the-final-say
Relevant section:
When studying childbirth, researchers look at hospital records and note down how often certain outcomes happen after each kind of birth. For two reasons, this makes it difficult to study MRCs properly. First, MRCs are typically recorded as “elective caesareans”. But because most electives are scheduled to mitigate a risky complication, researchers say it is unfair to align their risks with those of MRCs, where everything might be fine.
Second, the risk of vaginal birth is often underestimated, so the comparison is skewed. This is because researchers do not always account for emergency caesareans as an outcome of attempted vaginal births. In fact, many older studies lump in the emergency C-section risk with the risk of all other caesareans, despite the fact that they are clearly more dangerous and almost always the result of a vaginal birth not going to plan. As Nice makes clear, ideally, studies would compare people planning a C-section with those planning a vaginal birth, but this information is rarely available.
These factors make it very tricky to estimate the risk of choosing a C-section versus planning a vaginal birth, but not impossible. In 2021, a team of Canadian researchers found a hospital database in Ontario that, unusually, had logged MRCs. This allowed them to compare MRCs to other low-risk pregnancies where the plan, but not necessarily the outcome, was a vaginal birth.
The data shocked the study’s head author, Darine El-Chaâr, a perinatal researcher at the Ottawa hospital. In the planned vaginal birth group, there was a higher percentage of negative outcomes compared with the MRC group, driven by serious vaginal tears and babies admitted to intensive care. “I myself am challenged by the data,” she says, underlining that she believes vaginal birth is natural. “I wanted it to be the other way around.”