Comparison between atosiban and nicardipine in inducing hypotension during in-utero transfers for threatening premature delivery.

Background: The aim of this study was to compare the frequency of hypotension induced by oxytocin antagonist atosiban and nicardipine.

Methods: This case-control study enrolled 14 pregnant women presenting with threatening premature delivery treated with atosiban and managed by a physician-staffed Emergency Medical Service Department (French Emergency Medical Service system) during inter-hospital transfers. A control group of 42 consecutive pregnant women presenting with threatening premature delivery managed during inter-hospital transfers during the same period and treated with nicardipine was set up. The control group was recruited after matching on confounding variables: age 38 years or less and no previous cardiovascular disease to avoid factors related to the occurrence of cardiovascular events, duration of out-of-hospital management of at least 60 min to have similar likelihood of side-effect occurrence, and parity 2 or less and gestational age from 25 to 32 weeks to make comparable groups from the obstetrical viewpoint. Frequency of hypotension was compared between the two groups.

Results: Hypotension was observed in two patients (8%) in the atosiban-group and in five patients (14%) in the nicardipine-group, which is not significantly different (P>0.99).

Conclusion: Despite the notion that oxytocin antagonist atosiban has limited or no systemic adverse effects, these results suggest that this cost-consuming drug does not avoid hypotension and cannot help to reduce the level of monitoring.