臀位分娩

胎儿横位于子宫内，先露部为肩。

类似的诱因，包括前置胎盘、羊水量异常、子宫畸形，在多胎妊娠中更常见。[1]Cunningham F, Gant N, Leveno K, et al. Williams obstetrics. 21 ed. New York: McGraw-Hill. 1997.[2]Kish K, Collea JV. Malpresentation and cord prolapse. In: DeCherney AH, Nathan L, eds. Current obstetric and gynecologic diagnosis and treatment. New York: McGraw-Hill Professional. 2002.[27]Enkin M, Keirse MJNC, Neilson J, et al. Guide to effective care in pregnancy and childbirth. 3rd ed. Oxford University Press. 2000.

临床检查和胎心听诊可帮助诊断。

超声明确先露部。