Background: Despite wide use of Atropine by midwives and physicians as an adjunct to labor, obstetric literature contains few references to this effect of the drug. This study was a double blind, randomized controlled trial of primigravidas in Iran to determine the safety and efficacy of Atropine on the labor progress.
Materials and Methods: One hundred primigravidas in uncomplicated spontaneous labor, cervical dilation less than 4 cm and cervical effacement less than 50% were randomly assigned into two groups: the experiment group (N=50) receiving 0.5mg Atropine and the control group (N=50) receiving placebo, with predetermined codes, single dose injected at the beginning of the active phase of labor. The groups were compared for Bishop score of cervix after 1 h of injection, duration of active phase of labor, duration of second stage of labor, Fetal tachycardia and bradycardia 0.5 and 1 hours after injection, Apgar score and birth weight. The accepted level of significance was P<0.05.
Results: The two groups of women did not differ in maternal age, gestational age, initial cervical effacement and dilation and mean birth weight. The mean change in the Bishop score of cervix after 1 h of injection was significantly higher in those receiving hyoscine (3.7 vs. 2.4, P<0.0001). Mean duration of the active phase was significantly shorter in case group (181 Min vs 229.7 Min, p<0.0001). There was a significant difference between two groups in the duration of the second stage of labor (26.5 Min vs 44.2 Min, P<0.0001). The fetal tachycardia and bradycardia occurred more frequently in patients in the Atropine group compared to the control group, after 0.5 hours of injection (14% vs 8%, P<0.6). The mean first and fifth-minutes Apgar score were not significantly different.
Conclusions: This small series suggests benefit in a single dose of Atropine for labor progress and represents the first attempt to evaluate the medication. However, more randomized clinical studies are needed to establish efficacy, safety, and optimal dose of Atropine for labor progress at term.