nonviability

Nonviability refers to the state or condition of being unable to survive, develop, or operate successfully within a given environment or context. The term denotes an absence of viability, the capacity to sustain life, growth, or function.

In biology and medicine, nonviable describes cells, tissues, or organisms that cannot live or proliferate. Nonviable embryos or fetuses cannot progress to a live birth under current conditions, and may lead to medical decisions regarding pregnancy outcomes. Viability assays determine whether cells are alive by metabolic activity or membrane integrity.

In obstetrics, fetal viability denotes the stage at which a fetus has a reasonable chance of extrauterine survival with appropriate care, varying with technology and clinical standards. A pregnancy may be deemed nonviable if it cannot progress or if continuing would pose undue risk.

In agriculture, seed viability measures a seed’s potential to germinate; nonviable seeds fail to germinate or produce weak seedlings under normal conditions.

In business and engineering, viability refers to the likelihood that a project, product, or venture will be economically or technically sustainable. A nonviable enterprise lacks acceptable market demand, profitability, or feasibility, and may be terminated or pivoted.

In ethics and law, viability shapes policy and regulation, such as definitions used in reproductive rights and the use of embryos in research; these definitions differ by jurisdiction and context.

Measurement of viability relies on domain-specific criteria, including growth, metabolic activity, reproducibility, or survival probability, and often informs decision-making about continuation or termination.