A Randomized Clinical Trial of Intra-fetal Versus Intra-amniotic Digoxin Prior to Second-Trimester Pregnancy Termination

Of the 1.2 million abortions each year in the U.S., approximately 12% take place in the second trimester of pregnancy. The preferred technique for second-trimester pregnancy termination is dilation and evacuation, or D&E. In 2006, 144,000 D&Es were performed in the U.S. Clinicians often achieve preoperative fetal asystole by a maternal transabdominal injection of digoxin. Prior to D&E, providers use digoxin to induce fetal death 1) for providers' preference to facilitate surgical delivery of the fetus, and/or 2) for patients who express a desire for fetal death prior to the abortion.

The use of digoxin to achieve preoperative fetal asystole is widespread, yet there are no evidence-based standards for how to best achieve fetal asystole prior to D&E. Digoxin has been administered by intracardiac, intrathoracic, intrafetal and intra-amniotic routes, with doses varying from 0.25 to 2mg. Clinicians who use digoxin usually inject it one to two days before the D&E. Only one study has assessed the effectiveness of digoxin at varying dosages ; this was a retrospective and nonrandomized analysis. Published failure rates are based on small numbers of patients and are therefore imprecise. Intrafetal digoxin injection may be more effective, but is a technically more difficult procedure than intra-amniotic injection. The pharmacodynamics of digoxin when used for feticide are also unknown. The objective of this study is to determine the optimum route for digoxin injection (intrafetal or intra-amniotic) that will maximize patient safety while maintaining effectiveness.