Am Fam Physician. 2008;78(1):116
Background: As the rate of primary and repeat cesarean deliveries rises (now at 30 percent of all deliveries), the rate of vaginal birth after cesarean (VBAC) is falling. The risk of serious peripartum complications with VBAC is low but present, leading some community hospitals to stop offering VBAC altogether. It is unclear, however, whether VBAC outcomes vary by the type of hospital (community or university) that offer them. DeFranco and colleagues assessed the risks of VBAC in community and university hospitals and in hospitals with and without obstetrics-gynecology (OB-GYN) residency programs.
The Study: This study involves a secondary analysis of data from a retrospective cohort of women with one or more cesarean deliveries. Data were collected from 17 hospitals (six university and five community with OB-GYN residency programs; and six community without residency programs). VBAC attempts were classified as a trial of labor in any woman with a previous cesarean, regardless of the eventual mode of delivery. Outcomes included VBAC attempt, failed VBAC, uterine rupture, maternal blood transfusion, and composite adverse outcome (i.e., uterine rupture; uterine artery laceration; and bladder, bowel, or ureter injury). The study population was stratified by planned delivery mode (VBAC versus repeat cesarean) and then subdivided into those planning to attempt VBAC at a university hospital or a community hospital. The groups were then reevaluated based on those attempting VBAC at hospitals with OB-GYN residency programs and those attempting VBAC at hospitals without residency programs.
Results: Of the 25,065 women in the cohort, 50 to 61 percent attempted VBAC at each type of hospital. There were significant differences between women delivering at university hospitals and at hospitals with OB-GYN residencies (more preterm deliveries, higher gravidity, lower maternal age, higher incidence of cigarette smoking, preeclamp-sia, and pregestational diabetes) and those delivering at community hospitals and hospitals without OB-GYN residency programs. Attempted VBACs occurred 32 percent more often in university hospitals than in community hospitals, with an equal failure rate of approximately 24 percent. Similarly, hospitals with OB-GYN residencies attempted VBAC 22 percent more often than those without. The only difference in outcome was a significantly increased rate of uterine rupture in community hospitals compared with university hospitals (1.2 versus 0.6 percent).
Conclusion: The risks of uterine rupture and other maternal complications from VBAC are low and generally do not differ by hospital setting. Although the rate of uterine rupture is significantly higher in community hospitals, the absolute risk difference is only 0.6 percent. Hospitals should offer VBAC depending on their ability to respond quickly to complications.