RESUMO
OBJECTIVE: To assess the effectiveness of hyoscine-N-butylbromide on the duration of the first stage of labor among nulliparous women. METHODS: A randomized double-blind placebo-controlled study among 126 nulliparous women admitted in the active phase of labor to a teaching hospital in Sagamu, Nigeria, from January to August 2018. Based on the inclusion criteria, women were recruited and randomized to the study or control group, and given intravenous hyoscine-N-butylbromide 20 mg (1 mL) or sterile water (1 mL), respectively, during the active phase. Labor progress and outcomes were compared between the groups. RESULTS: The mean ± SD duration of active phase of first stage of labor was significantly shorter in the hyoscine-N-butylbromide group (324.9 ± 134.6 min) than in the control group (392.7 ± 119.6 min) (P = 0.004). The rate of cervical dilatation was 1.4 ± 0.8 cm/h in the hyoscine-N-butylbromide group and 1.0 ± 0.5 cm/h in the control group (P = 0.004). There were no significant differences in fetal heart rate, maternal vital signs, or Apgar scores between the two groups. CONCLUSION: Hyoscine-N-butylbromide was found to be effective in shortening the duration of the first stage of labor without adverse outcomes for mother or neonate. The trial was registered with the Pan African Clinical trials Registry (PACTR), protocol number: PACTR201808146688942 (https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=3532).