Study of the effect of pethidine and phenergan on the electronic fetal heart rate monitoring and the neonate

Forty full term pregnant women were studied intra-partum. Twenty cases were given 100 mg pethidine IM, and the other twenty were given 50 mg phenergan IM. Fetal heart rate [FHR] monitoring was done for all cases. Both drugs produced a significant reduction of both long and short term FHR variability, while the reduction of both of them by phenergan was insignificant. About half of the cases studied showed diminished or disappearance of the normally occurring acceleration with uterine contractions, while 25% of cases showed no change at all. Most of the above changes were transient and were found to disappear at the end of the observation time. No adverse neonatal outcome was observed on using both drugs