Success Rate and Factors Associated With Trial of Labour After One Caesarean Section at Al Thawra Hospital in Ibb City, Yemen: A Retrospective Cohort Study
This retrospective cohort study of 180 women at Al Thawra Hospital in Yemen found that while chronic diseases significantly reduce the likelihood of a successful trial of labour after one caesarean section, factors such as induction of labour, episiotomy, gestational age determination by last menstrual period, and abnormal birth weight are strong positive predictors of success.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
For women who have previously given birth by surgery, the path to their next delivery often presents a difficult choice. They can opt for a planned repeat surgery, or they can attempt a trial of labour, a process where they try to give birth vaginally despite the scar on their uterus. This attempt is known as a trial of labour after caesarean. If successful, the result is a vaginal birth after caesarean, a outcome that generally offers a quicker recovery, fewer surgical risks, and lower costs for the healthcare system. However, the path is not without peril; if the labour does not progress, the woman must undergo an emergency surgery, which carries higher risks than a planned procedure. Because of these stakes, doctors and patients need to know which factors make a vaginal birth likely to succeed and which make it likely to fail. While this question has been studied extensively in wealthy nations with advanced medical infrastructure, the answer remains unclear in places where resources are scarce and medical teams face unique challenges.
In a retrospective study conducted at Al Thawra Hospital in Ibb City, Yemen, a team of researchers set out to map these factors for their local population. Yemen has faced a severe humanitarian crisis and a collapse of much of its healthcare infrastructure since 2015, creating an environment where standard medical guidelines might not apply. The researchers looked back at the medical records of 180 women who had exactly one previous caesarean section and attempted a trial of labour at the hospital between January and December 2025. They divided these women into two groups: those who successfully delivered vaginally and those who had to undergo a repeat caesarean section. By comparing the medical histories, pregnancy details, and delivery events of these two groups, the team sought to identify what actually happened in their specific setting to influence the outcome.
The study revealed that the success rate for these attempts was just under half. Out of the 180 women, 86 achieved a vaginal birth, while 94 required a repeat surgery. This success rate is lower than the global average often seen in high-income countries but aligns with findings from other resource-constrained regions. The researchers found that the presence of chronic health conditions, such as diabetes or high blood pressure, was a significant barrier to success. Women with these conditions were much less likely to deliver vaginally, a finding that suggests these mothers require careful medical preparation before labour begins. Conversely, the study identified several factors that were strongly linked to a successful vaginal birth. Women who had their labour induced, meaning it was started or sped up with medication or mechanical tools, were far more likely to succeed than those who went into labour on their own. This result was surprising because, in many other parts of the world, induction is often viewed as a risk factor for failure. The authors suggest this difference may be because, in their hospital, doctors only chose to induce labour for women who already appeared to have the best chances of success, effectively selecting a group that was primed to succeed.
Another powerful indicator of success was the performance of an episiotomy, a small surgical cut made to widen the vaginal opening during the second stage of labour. The data showed that women who received this procedure were overwhelmingly more likely to have a successful vaginal birth. The researchers clarify that this does not mean the cut itself causes success; rather, it is a sign that the labour was progressing well enough to warrant this final push to avoid a last-minute surgery. Similarly, the weight of the baby played a role, though in a complex way. Babies with weights that fell outside the normal range—either very small or very large—were associated with higher success rates in this specific group. This counterintuitive finding likely stems from the fact that very small babies are easier to deliver, and their presence in the "abnormal" category may have balanced out the difficulties usually caused by larger babies. The study also noted that women who had previously given birth vaginally before their first caesarean were more likely to succeed, though this factor became less clear when all other variables were considered together.
When the women who failed their trial of labour were examined, the reasons for their repeat surgeries were telling. The most common cause was obstructed labour, where the baby simply would not move down the birth canal, followed by concerns about the baby's well-being during the process. A notable number of women also had their surgeries due to tenderness at the site of their previous scar, a sign that the medical team was being cautious about the risk of the uterus tearing. The study concludes that while the overall chance of success is roughly fifty-fifty in this setting, the outcome is heavily influenced by the mother's health history and specific events during labour. The findings highlight the urgent need for tailored advice for women in similar low-resource environments, emphasizing that those with chronic illnesses need extra support, while others might benefit from standardized protocols that carefully monitor labour progress. The authors stress that their results are specific to their hospital and the unique challenges of the region, suggesting that future work is needed to build local guidelines that can safely guide more women toward a successful vaginal birth.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.