Nifedipine versus nitroglycerin for acute tocolysis in preterm labour: a randomised controlled trial

Ajay Dhawle, Jaswinder Kalra, Rashmi Bagga, Neelam Aggarwal


Background: To compare the safety & efficacy of oral nifedipine with transdermal nitroglycerin in the inhibition of preterm labour.

Methods: This study included 84 women in preterm labour, randomly divided into two groups, 43 receiving oral nifedipine and 41, transdermal nitroglycerin (NTG). Patients in preterm labour with a single gestation, between the 26th and the 34th week and no contraindication for tocolysis were selected. Women with fetal malformation and medical or obstetric diseases were excluded. The variables analyzed were: delay in delivery for 48 hours, 7 days or more than 7 days, period of gestation at delivery, side effect profile of drugs & neonatal outcomes.

Results: Mean prolongation of pregnancy with NTG (29.04 days) was similar to that of nifedipine (34.46 days). Nifedipine was significantly more successful in prolonging pregnancy beyond 48 hours, especially in women with advanced cervical dilatation (>3 cm). Failure of acute tocolysis, defined as delivery within 48 hours, was significantly more common with NTG (31.7 %) as compared to nifedipine (11.6 %). Headache was significantly higher in the NTG group (41.5 %) compared to nifedipine group (4.7 %). The neonatal outcomes in terms of the mean birth weight, incidence of low birth weight and very low birth weight babies, need and duration of neonatal intensive care was similar in both groups.

Conclusions: Oral nifedipine is a safe and effective tocolytic with a lower failure rate and better side effect profile as compared with transdermal nitroglycerin.


Preterm labour, Nifedipine, Nitroglycerin, Tocolysis

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