Objective To compare the effects of patient-controlled continous epidural infusion of ropivacaine and pethidine intramuscular injection in induction of labor analgesia in midpregnancy.

• 目的比较PCA(患者自控)注药镇痛泵连续硬膜外注入盐酸罗哌卡因和度冷丁肌注在中孕引产镇痛中的效果。