Randomised controlled trial of effect of terbutaline before elective caesarean section on postnatal respiration and glucose homeostasis

Aim-To determine if terbutaline given to mothers before elective caesarean section facilitates neonatal respiration and metabolism. Methods-A randomised controlled trial of 25 full term infants delivered by elective caesarean section was conducted. The mothers received a continuous infusion of terbutaline or saline 120-0 minutes before birth. Umbilical ar tery blood was collected at birth and analysed for blood gases and catechol amines. The lung function of each infant was assessed two hours after birth , and blood pressure, heart rate, blood glucose and body temperature were m onitored until 24 hours of age. Results-The infants of the treated mothers (n=13) had significantly higher dynamic lung compliance (p<0.001), lower airway resistance (p<0.001), and r espiratory frequency than control infants (n=12). Blood glucose and adrenal ine concentrations were significantly higher in the treated group (p=0.0014 and p<0.01). None of these infants had any clinical respiratory difficulti es; there were two cases of transient tachypnoea in the control group. No n egative side effects due to the terbutaline treatment were seen among the i nfants. The mothers felt no discomfort caused by the terbutaline infusion, although they bled more during surgery (p=0.03). Conclusion-Stimulation of the beta adrenoceptors in utero with terbutaline infusion to the mothers promotes neonatal respiratory and metabolic adaptat ion after elective caesarean section.