Vaginal Birth After Cesarean, commonly known as VBAC, is an option for individuals who have previously delivered a baby via C-section. It allows a person to attempt a vaginal delivery in a subsequent pregnancy, offering an alternative to a repeat C-section. This article explores the various aspects that influence the likelihood of a successful VBAC.
Understanding VBAC Success Rates
The general success rate for VBAC ranges from 60% to 80% for suitable candidates. This means that for every 10 people who attempt a trial of labor after cesarean (TOLAC), approximately 6 to 8 will achieve a vaginal birth. For those who have had one C-section, the success rate can be as high as 70% in the U.S.. These are average statistics, and individual outcomes vary based on personal and medical considerations.
The likelihood of a successful VBAC decreases if a person has had two or more prior C-sections, dropping to about 50%. If a previous VBAC was successful without complications, the chances of future vaginal deliveries are higher. These rates highlight that while VBAC is a viable option for many, it is not guaranteed, and careful evaluation of individual circumstances is necessary.
Factors Influencing VBAC Success
The type of incision from a previous C-section influences VBAC success. A low transverse incision, a horizontal cut across the lower, thinner part of the uterus, carries the lowest risk of uterine rupture and is most favorable for VBAC. In contrast, a low vertical incision has a higher rupture risk, and a high vertical or “classical” incision in the upper uterus disqualifies an individual from attempting VBAC.
The reason for the previous C-section plays a role. If the prior C-section was due to a non-recurring issue, such as fetal malposition or preeclampsia, the chances of VBAC success are higher. If the previous C-section resulted from labor dystocia, meaning labor did not progress due to issues like the cervix not dilating or effacing, the success rate for VBAC are lower.
Having a history of a previous vaginal birth, either before or after a C-section, increases the likelihood of a successful VBAC. Studies indicate that a prior vaginal delivery more than triples the chances of VBAC success. The number of prior C-sections impacts the success rate.
Maternal factors, such as age and Body Mass Index (BMI), affect VBAC outcomes. Being over 35 years old or having obesity decrease the chances of a successful VBAC. Labor characteristics, including spontaneous labor onset versus induction, influence success rates. Spontaneous labor leads to higher VBAC rates compared to induced labor.
Fetal factors, such as fetal size and position, contribute to the likelihood of success. A very large fetus, especially in relation to the pelvis, reduces the chances of a successful VBAC.
Potential Risks and Considerations
The primary concern is uterine rupture, a serious complication where the previous C-section scar on the uterus tears open during labor. This occurs in less than 1% of VBAC attempts, with a risk of about 0.9% for those with a low transverse incision. A uterine rupture is life-threatening for both the birthing person and the baby, necessitating an emergency C-section.
An unsuccessful VBAC attempt, also known as a failed trial of labor after cesarean (TOLAC), leads to a repeat C-section. This unplanned C-section carries risks that can be higher than those of a planned repeat C-section. These increased risks include serious bleeding and infection.
Other less common complications associated with attempting a VBAC include increased blood loss and infection. Healthcare providers assess individual risk factors to determine the appropriateness of a VBAC attempt.
Maximizing Your Chances of a Successful VBAC
Choosing a healthcare provider and facility that are supportive of VBACs enhances the chances of success. Finding a hospital with high VBAC success rates and policies that support vaginal births after a prior C-section is beneficial. These facilities have the necessary resources and experienced staff to manage the labor safely.
Education and preparation are important for individuals considering VBAC. Understanding the process of labor, potential challenges, and various coping mechanisms helps build confidence and manage expectations. Attending childbirth classes, especially those focused on VBAC, provides valuable insights and practical knowledge.
Building a strong support system, which may include a doula, partner, or family members, provides emotional and physical assistance during labor. This support reduces anxiety and empowers the birthing person throughout the process. A supportive environment contributes to a more positive birthing experience.
Maintaining a healthy lifestyle before and during pregnancy influences VBAC outcomes. This includes following a balanced diet, engaging in appropriate exercise, and managing stress effectively. For example, studies suggest that walking or jogging at least 200 minutes per week increases the likelihood of a successful VBAC.
Patience and flexibility during labor are beneficial, as labor is unpredictable. Allowing labor to begin spontaneously, if possible, improves success rates. Open communication with the healthcare team about preferences and being prepared for potential changes in the birth plan are valuable.