Physicians have used meperidine (Demerol), an analgesia agent, in the management of labor since its introduction in the late 1940s. Meperidine for management of dystocia during the first stage of labor became widespread after early observational studies found that meperidine increased uterine contractility. This was particularly true in areas where epidural anesthesia is not readily available. Recent studies, however, have shown that meperidine does not increase uterine contraction and does not affect duration of labor. Sosa and colleagues conducted a randomized controlled trial to examine meperidine use in the management of women with dystocia during the first stage of labor.

The study included women with a term singleton pregnancy, vertex presentation, ruptured membranes, cervical dilation between 4 and 6 cm. The participants were diagnosed with contractility dystocia or required active labor management, defined as amniotomy with or without oxytocin (Pitocin) augmentation. Participants were randomized to receive meperidine (100 mg over 15 minutes) or placebo. The main outcome was the duration of labor from intervention to expulsion of the fetal head. Secondary maternal outcomes included mode of delivery and obstetric surgical procedures, need for oxytocin augmentation, level of pain defined by the Visual Analog Scale (VAS), and adverse side effects. Secondary neonatal outcomes included neonatal depression defined by the Apgar score, acid-base balance in the arterial and venous umbilical cord blood samples, admission to the neonatal intensive care unit, and standardized neurologic assessment scores.

In the final analysis of 407 women, 205 received meperidine. Participants in the two groups had no statistically significant differences. The authors found no differences between the intervention and placebo groups in duration of labor or in any of the maternal secondary outcomes. The VAS pain assessment also was similar in both groups. Women in the intervention group were more likely to have infants with lower Apgar scores, umbilical artery acidosis, and the need for admittance to the neonatal intensive care unit.

The authors conclude that meperidine offers no maternal benefits and can cause potentially harmful neonatal effects. Therefore, they suggest that meperidine should not be used for active management of dystocia during the first stage of labor.