The Effect of Intramuscular Administration of Dexamethasone Alone or in Combination with Hyoscine Butylbromide in Shortening the duration of Induced Labor in Primigravidas

Background: Induction of labour is common in clinical practice and is usually troublesome in primigravidas. Obestatricians are always in search of the best method of induction to ensure the best maternal and fetal outcome. Aim of Study: To evaluate the effect of Intramuscular (IM) administration of dexamethasone alone or in combined with Hyoscine Butylbromide (HBB) on the duration of labour induction in primigravidas. Patients and Methods: A randomized controlled study was conducted at the Obstetrics and Gynecology casualty department at Kasr Al-Ainy Hospital (Cairo University, Egypt) in the period from November 2015 to April 2016. 150 primigravidas with a singleton living healthy fetus who underwent Induction of Labour (IOL) participated in the study. They were randomly allocated into 3 groups: Group A where 50 women received IM dexamethasone (8mg) 6 hours prior to induction then IM 2ml saline at the onset of the active phase, Group B where 50 women received IM dexamethasone (8mg) 6 hours prior to induction then IM HBB (40mg) at the onset of the active phase and Group C (control) where 50 women received two IM saline injections (2mL) 6 hours prior to induction and at the onset of the active phase. IOL was done using 2.5mIU/min intravenous drip of oxytocin (in 500mL lactated Ringer's solution), increasing the dose by 2.5mIU/ml every 20 minutes until labour started. Amniotomy was done at a cervical dilatation of ≥6cm, if spontaneous rupture of the membranes had not spontaneously occurred. All participants were monitored by a partogram and continuous CTG throughout labor. Results: Both groups A and B showed significant shortening of the duration of the latent phase (3.4 ±0.6 and 3.6±0.7 vs 4.5±0.6hrs), the duration of the active phase (3.7 ±0.7 and 3.7±0.6 vs. 4.8±0.7hrs), the duration of the 2 nd stage (21.6± 5.3 and 21.9±7.2 vs. 30.0±5.3 minutes) as well as the duration of the 3 rd stage (6.3 ± 1.7 and 7.5± 1.9 vs. 10.0±2.8 minutes) respectively when compared to the control group ( p-value <0.001 for all). No statistical significant differences were noticed in neonatal Apgar score at 1 and 5 minutes between the three groups. Correspondence to: Dr. Omneya Helal, E-Mail: dromneya@hotmail.com Conclusions: Intramuscular injection of dexamethasone alone or in addition to hyoscine butylbromide was found to shorten the duration of induced labour in primigravidas, with no observed maternal or neonatal complications.