From the Guidelines
The soonest a Vaginal Birth After Cesarean (VBAC) can typically be attempted is 18-24 months after a previous cesarean delivery. This waiting period is recommended to allow the uterine scar to heal completely, reducing the risk of uterine rupture during labor, as suggested by guidelines from the American Academy of Family Physicians 1. The risk of uterine rupture decreases significantly when this interval is observed. For women who become pregnant sooner than 18 months after a cesarean, VBAC may still be possible but carries a somewhat higher risk that should be discussed with their healthcare provider. Key considerations for VBAC include the type of previous cesarean incision, the reason for the previous cesarean, maternal health, and current pregnancy conditions, emphasizing the importance of individualized care 1.
Important Considerations for VBAC
- The decision to attempt VBAC should be made in consultation with an obstetrician.
- Continuous fetal monitoring and immediate access to emergency cesarean delivery facilities are essential safety requirements for any VBAC attempt.
- Women who have had a previous vaginal birth have a high probability of VBAC, and physicians should encourage these women to plan for VBAC unless specific contraindications exist 1.
- Short-term maternal outcomes are as good or better with VBAC compared to repeat cesarean delivery, although perinatal mortality is higher, highlighting the need for careful risk assessment and management 1.
Safety and Efficacy of VBAC
The safety and efficacy of VBAC are supported by guidelines that emphasize the importance of discussing benefits and harms with patients, considering their individual risk factors, values, and preferences 1. The choice between VBAC and repeat cesarean delivery should be based on the best available evidence and patient-centered care principles. Given the potential risks and benefits, VBAC can be a safe and viable option for many women, provided that they are appropriately selected and managed by experienced healthcare providers.
From the Research
VBAC Timing
The soonest a Vaginal Birth After Cesarean (VBAC) can be done is a topic of interest for many women who have had a previous cesarean delivery. According to the available evidence:
- A study published in 2005 found that women who attempted VBAC at or beyond 40 weeks of gestation were more likely to have a failed VBAC, but the risk of uterine rupture or overall morbidity was not significantly increased 2.
- Another study published in 2015 compared induction of labor versus expectant management for women with a prior cesarean delivery and found that induction of labor at 39 weeks was associated with a higher chance of VBAC, but also a higher risk of uterine rupture 3.
- A 2022 retrospective cohort study found that artificial rupture of membranes (AROM) as a mode of induction of labor in women with a previous cesarean section was a safe and efficient practice with high rates of successful VBAC 4.
Key Considerations
When considering the timing of a VBAC, the following points are important:
- The American College of Obstetricians and Gynecologists recommends that VBAC be performed in hospitals equipped to care for women at high risk 5.
- Labor induction is not contraindicated in women with a prior cesarean, but sound judgment, clinical precautions, and specific consent are required 6.
- Nurses caring for patients undergoing VBAC should be able to recognize and respond to the signs and symptoms of uterine rupture, including nonreassuring fetal monitor tracing 5.
Gestational Age
In terms of gestational age, the evidence suggests that:
- VBAC can be attempted at 39 weeks of gestation, but the risk of uterine rupture is higher compared to expectant management 3.
- Women who attempt VBAC at or beyond 40 weeks of gestation are more likely to have a failed VBAC, but the risk of uterine rupture or overall morbidity is not significantly increased 2.
- AROM as a mode of induction of labor can be used at term gestation, with high rates of successful VBAC 4.