The principles of autonomy, beneficence, nonmaleficence, and justice can guide clinicians in finding ethical approaches to the treatment of women who have psychiatric disorders during preconception, pregnancy, and postpartum. Table 1 summarizes some clinical dilemmas in perinatal mental health care, the ethical conundrums posed by these situations, and guiding principles or tools that can help clinicians resolve ethical conflicts. The concept of relational ethics helps resolve apparent mother-offspring ethical conflicts, and the practice of preventive ethics helps anticipate and reduce the risk of ethical dilemmas and adverse clinical outcomes. These central principles suggest the following guidelines in caring for perinatal women: In situations that seem to pit the needs of a pregnant or postpartum woman against the needs of her fetus or baby, reframe the problem to find a solution that most benefits the mother-baby dyad while posing the least risk to the dyad. In evaluating a pregnant woman's ability to make autonomous, informed decisions about medical care, assess her ability to decide on behalf of both herself and her fetus. When explaining the risks of treatments such as psychotropic medication during pregnancy, avoid errors of omission by also explaining the risks of withholding the treatments. Apply the principle of justice to ensure that women are not stigmatized by having psychiatric disorders or by being pregnant. When screening for maternal psychiatric symptoms, ensure that the benefits of screening outweigh the ethical costs by designing effective follow-up systems for helping women who have positive screens. When treating women of reproductive age for psychiatric disorders, proactively discuss family planning and, when appropriate, the anticipated risks of the illness and the treatment during future pregnancies. Offer preventive interventions to reduce these risks.