Background: ethical issues that arise during the care of a pregnant woman with cancer are challenging to physicians, policymakers, lawyers, and the bioethics community. This article is restricted to a discussion of ethical dilemmas and controversial case reports, mainly focused before the third trimester of pregnancy, when a conflict could exist between cancer and pregnancy outcomes.Methods: published literature was retrieved through searches in PubMed or Medline, CINAHL, the Cochrane and Google Academic in April 2020, using appropriate controlled keywords (cancer, neoplasm, pregnancy, ethics). Results were restricted to review articles, ethical perspectives, clinical practice guidelines and case-based teaching guides.Discussion: when a conflict arises in the maternal-foetus dyad, like the one related with cancer treatment and the risk of foetal demise, a range of ethical frameworks might be useful to consider in the decision-making process. Pragmatic theoretical approaches include case-based analysis, ethics of care, feminist theory, and traditional ethical principlism using the framework of autonomy, beneficence, non-maleficence, and justice. Also, societal and practitioner values could add value and an ethics consultation may be helpful to mediate conflict resolution. The physician must balance autonomy and beneficence-based obligations to the pregnant woman with cancer, along with beneficence-based obligations to the foetus.Conclusions: ethical challenges have received less attention in the literature, particularly before the third trimester of pregnancy. Best, unbiased and balanced information must be granted both to the patient and to the family, regarding the benefits and harms for the woman herself as well as for the foetal outcome.