头先露的阴道助产术包括产钳助产术和胎头负压吸引术。在第二产程中判断胎头位置及胎方位是阴道助产成功的关键。胎头最低位置于坐骨棘2 cm以下，胎方位为枕前位者，助产风险相对小。产科医生要严格把握阴道助产的手术指征，并与患者充分沟通。临床医生的判断能力，培训经历以及临床经验是助产成功的重要因素。

Instrumental vaginal delivery technique for fetus in cephalic presentation includes forceps delivery and vacuum extraction. Assessment of the fetal head position and position prior in the second stage of labor is the key point for successful instrumental vaginal delivery. When the lowest point of fetal head is lower than 2 cm of ischial spines and occipitoanterior, the fetal appears a relatively low risk of instrumental vaginal delivery. Obstetricians should strictly grasp the indication of instrumental vaginal delivery, and should communicate with the patients well. Clinician′s judgment, training experience and clinical experience are the important factors for successful instrumental vaginal delivery.