Objective: To compare the effectiveness of 1.0 mg intra-fetal or intra-amniotic digoxin to achieve fetal asystole before second-trimester surgical pregnancy termination.
Methods: In a randomized trial, women received 1.0 mg transabdominal intra-fetal or intra-amniotic digoxin on the day of laminaria placement before dilation and evacuation between 20 and 24 weeks of gestation. The primary outcome was incidence of fetal asystole, documented immediately before dilation and evacuation. We planned to analyze the primary outcome by original group assignment as well as by as-treated and per-protocol populations. A sample size of 270 was needed to detect an 8% difference in failure rates between groups. Prespecified secondary outcomes included the incidence of adverse events, side effects, and procedural differences.
Results: Between January 2012 and January 2013, we screened 381 women and randomized 270 women to receive intra-fetal (n=136) or intra-amniotic (n=134) digoxin. Characteristics were similar across groups; the mean gestational age was 21.6 weeks (standard deviation 1.2). The proportion of fetal asystole was higher in the intra-fetal group (128/135 [94.8%]) than the intra-amniotic group (107/130, 82.3%; relative risk of failure to achieve asystole 3.41, 95% confidence interval 1.52-7.68). Results were similar in the as-treated and per-protocol populations. There were no significant differences in adverse events or side effects and no differences in injection duration, operative time, or estimated blood loss.
Conclusion: Administration of intra-fetal injection of digoxin led to a higher proportion of participants achieving fetal asystole within 24 hours than intra-amniotic injection.
Clinical trial registration: ClinicalTrials.gov, https://clinicaltrials.gov, NCT01047748.