Prevention of prolonged labour in term nulliparas with oxytocin alone versus with oxytocin and an antispasmodic

Background: Poor progress of labour is a common problem with nulliparous deliveries. It occurs when the cervical dilatation rate in the active phase of the first stage of labour is <1cm/hr, and is mainly due to poor uterine contractions or slow cervical dilatation. Without interventions, poor progress could degenerate into prolonged labour which is associated with increased maternal and perinatal morbidity and mortality.

Augmentation of labour with oxytocin is the traditional management for poor progress as it enhances uterine contractions. At times, despite adequate uterine contractions poor progress will persist due to cervical smooth muscle spasms. Antispasmodics can relieve smooth muscle spasms.

Aim/objective: This study compared the duration of labour in term nulliparous parturients with poor progress following augmentation with oxytocin alone versus with oxytocin and an antispasmodic (drotaverine).

Methods: The study was a single-blinded randomized controlled trial involving 156 term nulliparous parturients with poor progress of labour, that were randomized into two groups in eight months. Each group had 78 parturients which were augmented with either oxytocin with placebo or oxytocin with drotaverine. They were monitored until delivery and the duration of labour in both groups after the intervention was compared. Data obtained were analysed using SPSS version 23 software. The level of significance was set at 0.05.

Results: The two groups were similar in their sociodemographic characteristics, and the mean pre-intervention duration of labour was also similar (6.02 ±2.04 vs. 6.09± 2.07hr p=0.23). In this study 135(86.5%) parturients had vaginal delivery while 21(13.5%) had emergency caesarean section. Among those who had a vaginal delivery, the mean duration of labour following augmentation was significantly shorter in the oxytocin-drotaverine group than in the oxytocin-placebo group (6.20 ±0.40hrs vs. 6.64±0.34hrs, MD- 26.4minutes, p<0.01). There was no difference in the duration of the second stage of labour in both groups.

Conclusion: The use of drotaverine with oxytocin in managing poor progress of labour in term nulliparous women leads to a significantly shorter duration of the first stage of labour than oxytocin alone.