Recurrent shoulder dystocia: analysis of incidence and risk factors.

OBJECTIVES: To determine the rate and associated risk factors for recurrent shoulder dystocia (SD). STUDY DESIGN: A retrospective analysis was performed of patients delivered from January 1991 to June 2001. Patients with and without recurrent SD were identified and compared. RESULTS: Among the 267,228 vaginal births during the study period, there were 1904 cases of SD (0.7%) and 270 patients with one additional vaginal birth. The recurrent SD rate was higher than the general population (3.7% versus 0.7%, odds ratio 7.36, 95% confidence interval 3.68 to 14.23, p < 0.001). Patients with recurrent SD had a slightly higher mean birth weight with the second delivery, but this difference was not statistically significant (4173 ± 544 g versus 4017 ± 577 g, p = 0.39). CONCLUSION: Prior SD is a risk factor for recurrence in a subsequent delivery, but our results demonstrate that the rate appears to be lower than previously estimated. Most variables, including birth weight, do not appear to be useful parameters in predicting recurrence.

Vaginal birth after cesarean section: risk of uterine rupture with labor induction.

We assessed the rate of uterine rupture in patients undergoing labor induction for attempted vaginal birth after cesarean (VBAC). A retrospective study was performed of data from a computerized database. Deliveries from January 1, 1998, to June 30, 2001, in the Southern California Kaiser Permanente system were reviewed and various perinatal characteristics analyzed. A total of 16,218 patients had a prior low transverse cesarean section. Of these, 6832 (42.1%) had a trial of labor. Successful VBAC occurred in 86% of patients with spontaneous onset of labor and 66% of patients with labor induction ( p < 0.001). The uterine rupture rate was not different between patients with spontaneous or induced labor (1.0% versus 1.2%, p = 0.51). Similarly, there was no significant difference between oxytocin or prostaglandin E2 induction (1.4% versus 1.0%, p = 0.59). In our study, labor induction did not appear to increase the risk of uterine rupture in women attempting VBAC.