Overview: A warning for late-stage Cesareans
Recent findings from University College London (UCL) researchers suggest that Cesarean births performed during advanced stages of labor are associated with a higher risk of scar formation near the cervix. This location of scarring is important because it has been linked to an increased likelihood of preterm birth in future pregnancies. The study, published in the American Journal of Obstetrics & Gynecology, adds a new dimension to how clinicians consider the timing of a Cesarean and how to plan ongoing care for women who have had such procedures.
The study’s key findings
The research followed 93 women who underwent Cesarean delivery while active in labor, defined as a cervix dilated to four centimetres or more. Using transvaginal ultrasound between four and 12 months after birth, investigators mapped where the uterine scar formed and evaluated how well it healed. The results showed:
- As cervical dilation increased during labor, the Cesarean scar tended to be located lower in the uterus and closer to the cervix. Specifically, for each additional centimetre of dilation, the scar moved about 0.88 millimetres lower and nearer the cervix.
- About 58% of scars were situated in the upper womb, while 21% were near the cervix and another 21% within the cervix itself. Women who had a late-stage Cesarean were eight times more likely to have a cervix-proximate scar than those operated on earlier in labor.
The team also assessed scar healing. They found that scars near or within the cervix tended to heal less effectively, with a higher incidence of a scar defect called a “niche.” Such niches can harbour blood, potentially contributing to infertility, irregular bleeding, or complications in future pregnancies.
Why the location of the scar matters
UCL researchers explained that the cervix is a critical gateway to the birth canal, and scarring in this region may influence cervical competence and uterine function in subsequent pregnancies. Scar healing quality appears to be worse when the scar lies lower in the womb or near the cervix, which could heighten the risk of preterm birth for future children.
Implications for care and surgical technique
The authors stressed that understanding how labor stage affects scar location could improve postnatal care planning. For women who have had an advanced-labor Cesarean birth, clinicians might consider closer monitoring for signs of potential complications in later pregnancies and tailor counseling about preterm birth risk.
Lead author Dr. Maria Ivan of the EGA Institute for Women’s Health highlighted the novelty of the work: “Our study is the first to show how the stage of labor at Cesarean affects where the scar forms in the womb.” The researchers hope these insights will drive improvements in surgical techniques to minimize cervix-proximate scarring and to refine follow-up care tailored to women with late-pregnancy Cesareans.
Clinical and public health significance
With the rising rate of Cesarean births in high-income countries, including England where the procedure accounted for roughly 42% of deliveries in 2023/24, understanding long-term implications becomes increasingly important. This research supports a shift toward preventive strategies for preterm birth by addressing Cesarean-scar healing and potential preventative care in subsequent pregnancies.
What’s next in research and care
Researchers call for more studies to explore how Cesarean scar characteristics relate to gynecological symptoms and to identify interventions that improve healing. There is also a push to develop techniques that reduce cervix-near scarring without compromising immediate safety for mother and baby. In the meantime, clinicians can use these findings to better prepare women who undergo late-pregnancy Cesareans for future pregnancies and to discuss potential risks and monitoring needs openly.
Expert voices
Co-author Professor Anna David notes the need to translate findings into practice, while Tommy’s charity emphasizes the value of prediction and prevention in reducing preterm births after Cesarean births.
Context: A growing trend in births
As health systems observe higher Cesarean rates, informed, personalized postnatal care gains prominence. This study adds a crucial piece to the puzzle of how to safeguard future pregnancies for women who experience Cesarean births during active labor.
