Something like four in five caesareans are planned as opposed to emergency, and many are women who have already given birth the same way in a previous pregnancy.
This means that the proportion of women who have vaginal births after previously having caesareans is low.
This is despite the fact that vaginal births after caesareans are successful in as many as 76 percent of cases – in situations when these births are not working out, normally it simply means that the mother needs to give birth by another caesarean instead. So what’s the problem?
Clinicians’ professional bodies recognise that it is safe for most women to have vaginal births after caesareans, yet the quality of information they receive varies, and there is evidence that some clinicians are conservative about supporting women to let nature take its course.
This may be the result of obstetricians with less experience in giving the relevant counselling – or who lack the confidence to manage the labour of women who opt for a natural birth, which may be more complicated. Part of the problem is that the prospects for a successful vaginal birth in these circumstances varies from woman to woman.
The UK study
I have been involved in a study aimed at identifying predictive characteristics that could inform such a model. We used detailed clinical information for over 1 600 women who had attempted vaginal births after a previous caesarean. This is the largest UK study using consistently detailed data, and also includes about three times more women than any European studies.
Counting down. Mustafa Omar, CC BY
In keeping with previous studies, we found that factors that made such women more likely to have a successful vaginal birth included: not being overweight; having previously had a caesarean because the baby was in breech position; or having previously had a vaginal birth as well as a caesarean. Importantly, however, we also found that a previous caesarean in the second stage of labour – when the cervix has completely opened and the woman has started pushing – was strongly associated with a successful vaginal birth for a future pregnancy.
It is hoped that these findings will encourage clinicians to take the evidence into account when offering advice. Our next step is to test the same findings on a larger number of women using data from across Scotland – this first study concentrated on Scottish women from one hospital. In time, this should help develop a clinical tool that will support women to make more informed choices about how they give birth – hopefully making more women confident about their ability to give birth vaginally, if that is what they choose to do.