Study on the tocolysis effectiveness of nifedipin on uterine contraction in the management of preterm labor

ABSTRACT

A clinical trial was performed to evaluate the tocolytic possibility of nifedipin and to propose a treatment regimen for preterm labor in the National Hospital of Gynecol-Obstet from July 2003 to December 2003. There were 40 cases of preterm labor with gestational age 31 weeks and 3 uterine contractions per minute on average. Patients received a 10 mg sublingual loading dose every 20 minutes (maximum dose 40mg), and followed by 20 mg oral dose every 6- 8 hours. Result: the effectiveness in tocolysis of nifedipin is very fast. It took 60-80 minutes to arrest uterine contraction (70- 80%) (including contractions of high frequency and intensity), especially in urgent tocolysis. The lower the frequency and intensity is, the higher and sooner the effectiveness is. 92.5% of delivery were delayed for 48 hours. 82.85% were postponed until 36 weeks, and the mean time of prolonged pregnacy was 39 days. Side-effects were mild and transient and in normotensive pregnant women blood pressure was almost unaffected. This treatment regimen of nifedipin showed the effectiveness in preterm labor. In brief, nifedipin is an effective, safe, convenient and economic tocolytic agent. It may well represent the best suitable tocolytic alternative currently available and can be used widely in Viet Nam.