How to predict recurrent shoulder dystocia

Objective: Our aim was to determine the rate and risk factors for recurrent shoulder dystocia. Study Design: A retrospective analysis of patients diagnosed with shoulder dystocia was performed by searching a computerized database from January 1, 1993, to June 30, 1999 for the following information: (1) vaginal deliveries, either spontaneous or operative, (2) shoulder dystocia, (3) birth weight, (4) duration of second stage of labor, (5) parity, and (6) gestational diabetes. Statistical analyses included χ2 and t test. Results: There were 39,681 vaginal deliveries with 602 (1.5%) complicated by shoulder dystocia. Sixty-six patients underwent a subsequent vaginal delivery, and 11 (16.7%) experienced another shoulder dystocia. The odds ratio for a recurrent shoulder dystocia was 10.98 (P< .000001). Nine of the 11 patients with recurrent shoulder dystocia compared with 28 of 55 without a recurence were nulliparous women in their index pregnancy (P< .001). The mean fetal weights were 3885 g in the recurrent dystocia group and 3702 g in the group without recurrence (P< .03). Gestational age, operative delivery, and gestational diabetes were similar in the two groups. Conclusion: Factors that appear to increase the recurrence risk of shoulder dystocia include fetal weight and maternal parity. Prior shoulder dystocia is the single greatest predictive factor. (Am J Obstet Gynecol 2001;184:1427-30.)