Management of preterm labour

Editor—Steer and Flint stated in their article in the ABC of labour care that the use of sympathomimetics is generally the safest choice for the mother and the fetus and that calcium channel blockers cause significant hypotension.1 We disagree with this. In studies in pregnant women nifedipine has minimal cardiovascular and metabolic effects during clinical use, in contrast with β2 sympathomimetics such as ritodrine.2 Nifedipine in the management of preterm labour is associated with significantly fewer maternal side effects than ritodrine.3,4 In our study we never had to stop treatment in the nifedipine group because of severe maternal side effects, whereas we did in 12 patients in the ritodrine group.3 No patients in the nifedipine group had hypotension while receiving treatment. Two patients in the ritodrine group had such changes on the electrocardiogram that the drug had to be stopped; this did not occur in any of the patients in the nifedipine group. In our opinion, nifedipine is a safe and effective firstline tocolytic agent.