2014 年 2 巻 2 号 p. 65-71
The precise reporting of fetal station is important in the decision-making regarding whether instrumental vaginal delivery or cesarean section should be performed. However, accurate evaluation of fetal station is difficult because it is defined on the basis of a hypothetical vertical midline to the ischial spines. Moreover, during delivery, the fetal head descends anteriorly into the pelvis along the pelvic axis and not in the vertical direction. DeLee’s concept of fetal station, first reported in 1924, has been revised by taking into account the fetal head descent along the pelvic axis, and this concept has been in clinical use at the University of Tokyo Hospital since the 1970s.
In this review, we assess the problems associated with conventional fetal station and explain the new concept of fetal station based on the trapezoidal plane and assessment of head descent upon instrumental delivery.
