Obstructed labor and shoulder dystocia.

Dystocia of labor has become one of the leading indications for operative delivery during the past few years. Dystocia of the first stage of labor complicates 8-11% of all vertex delivery, and in the second stage of delivery it is at least as common. Dystocia may result in part from three factors: uterine activity, the fetus, and the pelvis. In each case of abnormal labor, assessment should be made according to those criteria. Shoulder dystocia is an infrequent, unanticipated, and unpredictable nightmare for the obstetrician. Although it is difficult to predict shoulder dystocia, effort should be made to prevent it. Tight glucose control in the management of diabetic patients will reduce the incidence of macrosomic fetuses. Cesarean section should be considered for diabetic women carrying fetuses with estimated fetal weight of greater than 4250g and for non-diabetic women carrying fetuses with estimated fetal weight of greater than 4500g. In all cases good clinical judgement can reduce the rate of shoulder dystocia. However, in some cases it remains a problem for the obstetrician and because it occurs so rarely, the care provider may have limited skills to manage this condition.