[Multicenter analysis of risk factors and clinical characteristics of shoulder dystocia]

To explore the risk factors and clinical characteristics of shoulder dystocia.

The data of 44 580 single pregnancy and full-term head delivery were colleceted in the Third Affiliated Hospital of Guangzhou Medical University, Nanfang Hospital, Shenzhen Nanshan Hospital, Peking University Shenzhen Hospital and Yue Bei People's Hospital from January 2008 to September 2013. Totally 116 cases of shoulder dystocia were defined as the shoulder dystocia group, and the others were in the control group. The clinical data of the two groups were analyzed retrospectively, including the maternal age, maternal height, pre-gestational body mass index, weight gain during pregnancy, gestational weeks, gravidity, parity, fundal height, fetal abdominal perimeter, shoulder dystocia medical history, macrosomia, gestational diabetes mellitus, pre-gestational diabetes mellitus, post-term pregnancy and the condition of labor stages.

(1) The incidence of shoulder dystocia was 0.260% (116/44 580). The maternal age, pre-gestational body mass index and weight gain during pregnancy in the shoulder dystocia group were higher than those in the control group (all P < 0.01). While the maternal height, gestational weeks, gravidity, parity, fundal height, abdominal circumference in the two groups had no significant difference (all P > 0.05). (2) In the shoulder dystocia group, the incidence of shoulder dystocia medical history (11.21%, 13/116), macrosomia (13.79% , 16/116), pre-gestational diabetes mellitus (7.76% , 9/116), post-term pregnancy (10.34%, 12/116), prolongation of maximum acceleration phase (8.62%, 10/116) and prolongation of second labor stage (7.76%, 9/116) were different from those in the control group[1.43% ( 636/44 464), 1.48% (658/ 44 464), 0.57% ( 252/44 464), 1.15% (513/44 464),0.72% (322/44 464), 0.65% (289/44 464), respectively; all P < 0.05]. (3) Logistic regression analysis showed that the risk factors of shoulder dystocia were maternal age over thirty-five years (OR = 1.116, 95%CI: 1.022-2.445), pre-gestational body mass index more than 27 kg/m(2) (OR = 1.893, 95% CI: 1.358-2.228), weight gain more than 20 kg during pregnancy (OR = 2.031, 95% CI: 1.749-3.231), shoulder dystocia medical history (OR = 2.138, 95%CI:1.564-3.853), macrosomia (OR = 3.276, 95% CI:2.315- 4.638), pre-gestational diabetes mellitus (OR = 3.261, 95% CI:2.237- 4.943), post-term pregnancy (OR = 1.473, 95% CI:1.003-2.721), prolongation of the maximum acceleration phase (OR = 2.022, 95% CI:1.681- 3.732), prolongation of second labor stage(OR = 1.943, 95% CI:1.285- 3.215).

Maternal age over thirty-five years old, pre-gestational body mass index more than 27 kg/m(2), weight gain more than 20 kg during pregnancy, shoulder dystocia medical history, macrosomia, pre-gestational diabetes mellitus, post-term pregnancy, prolongation of the maximum acceleration phase, and prolongation of second labor stage are risk factors and clinical characteristics of shoulder dystocia.