This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
In this study, researchers examined information from the health records of women who had 1 or more previous births by caesarean section. They found that:
- women who planned a vaginal birth (after a previous caesarean) were more than twice as likely to subsequently have pelvic floor surgery as those who planned another caesarean
- the risk of pelvic floor surgery during the average study follow-up period of 22 years was low (less than 3% of women).
The researchers stress that pregnant women who have had a previous caesarean birth also consider other information when thinking about how to give birth. For example, they may wish to consider how many more children they would like to have, as the risk of serious complications increases with each caesarean birth.
The findings will inform shared decision-making with pregnant women who had a previous caesarean birth.
For more information about pregnancy, visit the NHS website.
The issue: how should I give birth after a previous caesarean?
Around 1 in 4 births in the UK are by caesarean section. Some are planned because of a woman’s anxiety or previous trauma, for instance. Other reasons can include the baby’s position (breech) or the mother’s high blood pressure. Most women in the UK recover well after birth and have healthy babies, whether they have a vaginal or caesarean birth.
The National Institute for Health and Care Excellence (NICE) and Royal College of Obstetricians and Gynaecologists guidelines recommend that clinicians discuss the benefits and risks of vaginal and caesarean births and allow women to decide which is best for them.
Little research has explored the impact of this choice on long-term outcomes, such as women’s risk of pelvic floor disorders (such as pelvic organ prolapse, urinary incontinence and bowel incontinence). These disorders can reduce quality of life and wellbeing. They are usually managed by lifestyle changes (losing weight, for example) and pelvic floor exercises. However, around 1 in 8 women undergo surgery for symptoms by the age of 80 years.
Researchers examined whether someone’s planned mode of birth after a previous caesarean section affected their subsequent risk of having pelvic floor surgery.
What’s new?
The researchers analysed routinely collected data from more than 47,000 women in Scotland who gave birth after they had 1 or more previous caesarean section births. Pregnancies were of a single baby; twin or multiple births were not included. Most women (67%) had a planned vaginal birth.
Women were followed up for just over 22 years, on average. The study found that women who had a previous caesarean section:
- were more than twice as likely to have pelvic floor surgery if they planned a vaginal birth compared to planning another caesarean birth
- had a low risk of having pelvic floor surgery (less than 3% of women) during the study follow-up, regardless of the planned mode of birth.
The increased risk of having pelvic floor surgery was only seen in the women who actually gave birth vaginally as planned. Women who planned a vaginal birth but needed an unplanned caesarean section when they were in labour had a risk of pelvic floor surgery similar to those who had a planned caesarean section.
Why is this important?
These findings will inform discussions between women and their clinicians. They provide a fuller understanding of the risks and benefits of birth choices after a previous caesarean section. However, the future need for pelvic floor surgery is not the only information that women need to consider when thinking about how to give birth. The Royal College of Obstetricians and Gynaecologists suggests they also take into account, for example, how many more children they wish to have (since the risk of maternal complications increases with each caesarean section).
This was an observational study so cannot say with certainty whether vaginal birth led to the need for surgery. Also, as the researchers acknowledge, there may have been coding errors (for instance in the information they used to identify pelvic floor surgery). However, most routinely collected Scottish health data is considered to be high quality, and much is subject to regular quality checks, they say.
What’s next?
Women were relatively young (average age of 51 years) when the study was completed. Previous research suggests that while surgery for urinary incontinence is most commonly performed in women in their 50s, surgery for pelvic organ prolapse and rectal prolapse is most commonly performed when women are in their 60s or 70s.
Longer-term follow-up and additional studies including women using non-surgical treatments (such as pessaries) will further increase understanding of the relationship between mode of birth and women’s subsequent risk of pelvic floor disorders.
You may be interested to read
This is a summary of: Fitzpatrick K, and others. Planned mode of birth after previous cesarean section and risk of undergoing pelvic floor surgery: A Scottish population-based record linkage cohort study. PLoS Medicine 2022; 19: e1004119.
Other research from the same team.
The Royal College of Obstetricians and Gynaecologists' issues professional guidelines about birth after a previous caesarean birth; and provides information for pregnant women.
Funding: This study was funded by an NIHR Doctoral Research Fellowship.
Conflicts of Interest: One author has received fees and funding from industrial companies; see paper for full details.
Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.
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