Vaginal birth after cesarean section: trial of labor or repeat cesarean section? A decision analysis.

OBJECTIVE The risk of perinatal death associated with labor after previous cesarean section appears higher than with a repeated cesarean section. On the other hand, repeated cesarean sections are associated with increased maternal morbidity and mortality from placental pathologic conditions (previa or accreta) on subsequent pregnancies. The study was undertaken to analyze the decision for a trial of labor or a repeated cesarean section, after a prior cesarean section, with varying desire for an additional pregnancy. STUDY DESIGN A model was formulated using a decision tree, based on the reported risks of the two approaches. Sensitivity analysis was performed over a variety of probabilities (eg, chance of uterine rupture or neonatal death, chance of rescue cesarean section, desire for an additional pregnancy) and utilities (eg, use of hysterectomy or neonatal death). RESULTS The model favors a trial of labor if it has a chance of success of 50% or above and if the wish for additional pregnancies after a cesarean section is estimated at near 10% to 20% or above because the delayed risks from a repeated cesarean section are greater than its immediate benefit. The model was robust over a wide range of assumptions. CONCLUSION An optimal decision for a trial of labor or a repeated cesarean section is substantially determined by the wish for future pregnancies. The default option of a repeated cesarean section is not directly applicable in populations in which family planning often extends over two children.