Atosiban, an oxytocin receptor antagonist, is no better than other drugs in delaying or preventing preterm birth but has fewer maternal side-effects.
Tocolytic agents may postpone preterm delivery long enough to improve neonatal outcome, allow corticosteroids to be given to help the baby's lungs and other organs to mature and, if necessary, to allow transfer of the mother to a hospital that has facilities to provide neonatal intensive care. Tocolytic drugs called oxytocin receptor antagonists work by inhibiting the hormone oxytocin that stimulates labour. This review found that, although the oxytocin receptor antagonist atosiban resulted in fewer maternal side-effects than other tocolytic drugs (betamimetics), no benefit was shown in delaying or preventing preterm birth, and atosiban was associated with more infant deaths in one placebo controlled trial. Further well-designed trials are needed.