Drs Sharvit and colleagues describe their experience with a prospective cohort study of the safety and efficacy of the intra-amniotic administration of digoxin to cause feticide in pregnancies between 21 and 30 weeks of gestation that were complicated by a ‘severe or incurable fetal anomaly or malformation’ or for ‘exceptional psychosocial reasons’. Feticide was approved by a ‘special committee’. This study was reviewed and approved by the Meir Medical Center Institutional Ethics Committee, was registered with www.ClinicalTrials.gov, and was supported with institutional funds. The study offered enrolment to pregnant women who met strict inclusion and exclusion criteria, and only those women who provided informed consent were enrolled. Women who were enrolled received intra-amniotic digoxin followed by close observation of maternal digoxin levels and to determine whether fetal demise occurred. When this did not occur, potassium chloride cardiocentesis was performed. In 55 of 59 research subjects, digoxin was successful in causing feticide in 55 of 59 (93.2%) of cases. The other four patients, per study design, required potassium chloride cardiocentesis. None of the subjects experienced major complications related to the administration of digoxin. There were no instances of digoxin toxicity or chorioamnionitis. The authors conclude that this phase-I trial of the administration of digoxin followed by close observation and potassium chloride cardiocentesis, as needed, was effective and appears to be safe (Sharvit M, et al. BJOG 2019;126:885–9). Amniotic injection is a clinically easier procedure, because it requires a lower level of technical skills than cardiocentesis. The authors, correctly, call for further evaluation because a phase-I study, excepting rare exceptions, does not establish safety and efficacy in populations of patients with different characteristics. Dr. John Gregory (1724–1773), one of the inventors of professional ethics in medicine, cautioned against enthusiasm: clinical practices that lack a sufficient evidence base of acceptable outcomes (McCullough LB. John Gregory and the Invention of Professional Medical Ethics and the Profession of Medicine, 1998). Clinical practice based on enthusiasm has a very checkered history. For example, ‘despite the enthusiastic support published in Reader's Digest’, Cobb and colleagues performed a randomised, sham surgery-controlled study that concluded: ‘Internal-mammary-artery ligation probably has no effect on the pathophysiology of coronary-artery disease’ (Cobb et al. New Engl J Med 1959;260:1115–18). Enthusiasm has no place in professionally responsible obstetric and gynaecological practice, especially when another procedure is easier, and in circumstances that are psychosocially and ethically challenging (Chervenak et al. Professional Responsibility Model of Perinatal Ethics, 2014). To prevent such enthusiasm, we recommend that only centres with the commitment to careful follow-up and the capacity to safely perform cardiocentesis should consider contributing to the further evaluation called for by the authors. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.