Sublingual nitroglycerin versus intravenous ritodrine as tocolytic for external cephalic version: a double-blinded randomized trial.
OBJECTIVE
The purpose of this study was to compare the efficacy of sublingual nitroglycerin with that of intravenous ritodrine as a tocolytic agent for external cephalic version in nulliparous women.


METHODS
We performed a double-blinded, randomized trial. Nulliparous patients, between 36 and 40 weeks of gestation, were assigned randomly to receive either (1) an intravenous infusion of ritodrine (111 microg/min) for 20 minutes, followed by two puffs of sublingual placebo or (2) an intravenous infusion of sodium chloride 0.9% (placebo) for 20 minutes, followed by two puffs of sublingual 0.4 mg of nitroglycerin. Three minutes after the administration of the sublingual spray, an external cephalic version was attempted. The rate of successful external cephalic version and side effects was compared between groups.


RESULTS
Of 74 randomly assigned patients, 38 patients received intravenous ritodrine, and 36 patients received sublingual nitroglycerin. Although not statistically significant, the rate of the successful external cephalic version was higher in the ritodrine group compared with the nitroglycerin group (45% vs 25%, P =.075). The rate of headaches was higher in patients who received nitroglycerin (28% vs 8%, P =.02). Mean blood pressure and maternal heart rate were lower in the nitroglycerin group 10 minutes after the administration of the medication. However, there was no significant difference in the rate of palpitations, hypotension, or fetal bradycardia between the two groups.


CONCLUSIONS
When compared with intravenous ritodrine, sublingual nitroglycerin was associated with a higher rate of headache, lower blood pressure, and a trend toward a lower rate of successful external cephalic version.
Bujold
Emmanuel
E
Departments of Obstetrics and Gynecology, Sainte-Justine Hospital and University of Montreal, Montréal, Québec, Canada. ebujold@med.wayne.edu
Marquette
Gérald P
GP
Ferreira
Ema
E
Gauthier
Robert J
RJ
Boucher
Marc
M
D000286:Administration, Sublingual; D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use*; D010298:Parity; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012312:Ritodrine / Q000008:administration & dosage / Q000627:therapeutic use*; D015149:Tocolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D014710:Version, Fetal
D015149:Tocolytic Agents; D005996:Nitroglycerin; D012312:Ritodrine