How to critically evaluate positions on obstetric ethics.

We identify three tools for the critical evaluation of positions on obstetric ethics. The first is the distinction between descriptive and normative obstetric ethics. The second comprises the "Six Cs" of rigorous ethical analysis and argument: clarity, consistency, coherence, clinical applicability, clinical adequacy and completeness. The third is the avoidance of pitfalls that might arise from failing to acknowledge the inherent limitations of fields that contribute to normative obstetric ethics: law, region, professional consensus, uses of authority and philosophy.