A young pregnant woman whose fetus has been exposed to multiple teratogens consents to undergo serial percutaneous umbilical blood sampling (PUBS) to examine how exposure affects the fetus over time.Although these tests will not improve the fetus's outcomes and will expose it to some risks,the information gathered may help infants in the future.Which ethical principle is at greatest risk?

A) Autonomy.
B) Fidelity.
C) Nonmaleficence.
D) Beneficence.

Nonmaleficence is the ethical principle that focuses on avoidance of harm or hurt.The nurse must balance risks and benefits of care.Repeated PUBS may place the mother and fetus at risk for infection and increased pain,and the mother may be at risk for increased emotional stress.Fidelity refers to the agreement to keep promises,autonomy refers to freedom to make decisions without external control,and beneficence refers to taking positive actions to help others.