ABSTRACT
Preterm birth is the most important cause of perinatal mortality in Europe and North America. Tocolytic agents named beta 2-sympathicomimetics postpone delivery for 24-48 hours, but do not reduce perinatal mortality or morbidity. Calcium antagonists, in particular nifedipine, are more effective tocolytic agents than beta 2-sympathicomimetics in terms of delaying delivery. Meta-analyses have found that calcium antagonists statistically significantly reduced perinatal morbidity and that the number of maternal side effects was statistically significantly lower compared with beta 2-sympathicomimetics. Nifedipine also has the benefit of oral administration, in contrast with beta 2-sympathicomimetics which are administered intravenously. Nifedipine is therefore the first choice in the management of threatening preterm labour.
