Predicting Significant Maternal Morbidity in Women Attempting Vaginal Birth after Cesarean Section

ABSTRACT

Attempting vaginal birth after cesarean section (VBAC) places women at an increased risk for complications. We set out to identify factors that are predictive of major morbidity in women who attempt VBAC. A nested case-control study was performed within a large retrospective cohort study of women with a history of at least one cesarean. Women who attempted VBAC were identified and those who experienced at least one complication of a composite adverse outcome consisting of uterine rupture, bladder injury, and bowel injury (cases) were compared with those who did not experience one of these adverse outcomes (controls). We analyzed risk factors for major maternal morbidity using univariable and multivariable methods. The accuracy of the multivariable prediction model was assessed with receiver operator characteristic (ROC) curve analysis. Of 25,005 women with a history of previous cesarean, 13,706 (54.9%) attempted VBAC. The composite outcome occurred in 300 (2.1%) women attempting VBAC. Using logistic regression analysis, prior abdominal surgery (odds ratio [OR] 1.58, 95% confidence interval [CI] 1.2 to 2.1), augmented labor (OR 1.78, 95% CI 1.29 to 2.46), and induction of labor (OR 2.03, 95% CI 1.48 to 2.76) were associated with an increased risk of the composite outcome. Prior vaginal delivery (OR 0.39, 95% CI 0.29 to 0.54) was associated with decreased risk for the composite outcome. The ROC curve generated from the regression model has an area under the curve of 0.65 and an unfavorable tradeoff between sensitivity and specificity. Women attempting VBAC with a history of abdominal surgery or those who undergo augmentation or induction of labor are at an increased risk for major maternal morbidity, and women with a prior vaginal delivery have a decreased risk of major morbidity. The multivariable model developed cannot accurately predict major maternal morbidity.

KEYWORDS

Vaginal birth after cesarean section - VBAC - maternal morbidity - uterine rupture

REFERENCES

• 1 Macones G A, Peipert J, Nelson D B et al.. Maternal complications with vaginal birth after cesarean delivery: a multicenter study.  Am J Obstet Gynecol. 2005;  193 1656-1662
• 2 Landon M B, Hauth J C, Leveno K J National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery.  N Engl J Med. 2004;  351 2581-2589
• 3 McMahon M J, Luther E R, Bowes Jr W A, Olshan A F. Comparison of a trial of labor with an elective second cesarean section.  N Engl J Med. 1996;  335 689-695
• 4 Silver R M, Landon M B, Rouse D J National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network et al. Maternal morbidity associated with multiple repeat cesarean deliveries.  Obstet Gynecol. 2006;  107 1226-1232
• 5 Macones G A, Cahill A G, Stamilio D M, Odibo A, Peipert J, Stevens E J. Can uterine rupture in patients attempting vaginal birth after cesarean delivery be predicted?.  Am J Obstet Gynecol. 2006;  195 1148-1152
• 6 Grobman W A, Lai Y, Landon M B National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network et al. Prediction of uterine rupture associated with attempted vaginal birth after cesarean delivery.  Am J Obstet Gynecol. 2008;  199 30, e1-e5
• 7 Grobman W A, Lai Y, Landon M B National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU) et al. Development of a nomogram for prediction of vaginal birth after cesarean delivery.  Obstet Gynecol. 2007;  109 806-812
• 8 Grobman W A, Lai Y, Landon M B et al.. Does information available at admission for delivery improve prediction of vaginal birth after cesarean?.  Am J Perinatol. 2009;  26 693-701
• 9 van Goor H. Consequences and complications of peritoneal adhesions.  Colorectal Dis. 2007;  9 (Suppl 2) 25-34
• 10 Menacker F, Declercq E, Macdorman M F. Cesarean delivery: background, trends, and epidemiology.  Semin Perinatol. 2006;  30 235-241
• 11 Alexander J M, Leveno K J, Rouse D J National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU) et al. Comparison of maternal and infant outcomes from primary cesarean delivery during the second compared with first stage of labor.  Obstet Gynecol. 2007;  109 917-921
• 12 Cahill A G, Stamilio D M, Odibo A O et al.. Is vaginal birth after cesarean (VBAC) or elective repeat cesarean safer in women with a prior vaginal delivery?.  Am J Obstet Gynecol. 2006;  195 1143-1147
• 13 Grobman W A, Lai Y, Landon M B Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network et al. Can a prediction model for vaginal birth after cesarean also predict the probability of morbidity related to a trial of labor?.  Am J Obstet Gynecol. 2009;  200 56, e1-e6