★ Categories of dystocia Abnormal of the powers(uterine contractility and matenal expulsive effort Abnormalities of passenger(the fetus o Abnormalities of the passage(the birth canal) RENJI HOSPITAL3 RENJI HOSPITAL uAbnormal of the powers(uterine contractility and maternal expulsive effort) uAbnormalities of passenger(the fetus) uAbnormalities of the passage(the birth canal) Categories of dystocia