From the Research
The maximum dose of terbutaline that can be given to a pregnant mother during external cephalic version (ECV) is typically 0.25 mg administered subcutaneously. This single dose is generally considered safe and effective for uterine relaxation during the procedure. Terbutaline is a beta-2 adrenergic agonist that works by relaxing the uterine smooth muscle, which facilitates easier manipulation of the fetus from breech to cephalic presentation. The medication typically takes effect within 5-15 minutes after administration and lasts for approximately 2-4 hours.
Some key points to consider when administering terbutaline for ECV include:
- Side effects that should be monitored include maternal tachycardia, palpitations, tremors, and rarely pulmonary edema 1, 2.
- Blood pressure and heart rate should be monitored before and after administration.
- Terbutaline should be used with caution in mothers with cardiac disease, hypertension, hyperthyroidism, or diabetes.
- Alternative tocolytics that may be considered include nitroglycerin or nifedipine, though terbutaline remains commonly used due to its effectiveness and relatively good safety profile when administered as a single dose for ECV 3, 4.
It's worth noting that the most recent and highest quality study on this topic is from 2009 3, which compared oral nifedipine versus subcutaneous terbutaline tocolysis for external cephalic version. However, the study that directly answers the question of the maximum dose of terbutaline is from 2004 1 and 1997 2, which both support the use of 0.25 mg of subcutaneous terbutaline for ECV.