In which of the following situations should cord blood gases be obtained?

Obtaining cord blood gases is particularly indicated in situations where there is a concern for fetal well-being and potential hypoxia. In the case of a cesarean delivery for fetal compromise, there is a higher likelihood that the neonate may have experienced some level of oxygen deprivation. Analyzing cord blood gases in this situation provides crucial information about the infant's acid-base status and oxygenation, which can inform immediate neonatal care and intervention strategies.

This evaluation is essential to assess the need for resuscitation efforts and guides healthcare professionals in determining the appropriate course of action for the newborn. Understanding the metabolic and respiratory status of the neonate helps in the planning of further management and monitoring.

Other scenarios, such as a normal vaginal delivery or routine post-delivery checks, typically do not necessitate the collection of cord blood gases unless specific concerns arise. In the case of a non-stress test failure, while it indicates a potential issue with the fetus, the appropriate actions vary and may not require immediate cord blood analysis unless accompanied by additional distress indicators. Thus, option B stands out as the most appropriate situation for obtaining cord blood gases.