Randomised, double-blind, placebo controlled pilot study assessing nitroglycerin as a tocolytic.

Thirty-three women in preterm labour were randomised in a double-blind fashion to receive either transdermal nitroglycerin (n = 17) or placebo (n = 16). Both groups had significant (P < 0.001) change in the cervix prior to randomisation. The primary outcome measure was delivery within 48 hours of randomisation. Fewer women randomised to nitroglycerin treatment (6/17) were delivered within 48 hours, compared with the placebo treatment (10/16) (RR 0.56, 95% CI 0.27 to 1.19). This pilot study lends support to two case series published that suggest that transdermal nitroglycerin may be promising as a safe, effective means for tocolysis.