What is the primary purpose of the fetal scalp pH test?

The primary purpose of the fetal scalp pH test is to evaluate fetal acid-base status and potential distress. This test involves obtaining a blood sample from the fetal scalp during labor, which provides valuable information about the fetus's metabolic state.

A low pH indicates acidosis, suggesting that the fetus may be experiencing stress or hypoxia, which can be crucial for timely interventions to prevent fetal damage or stillbirth. It informs healthcare providers about the need for possible therapeutic interventions such as cesarean delivery if fetal distress is confirmed.

The other choices focus on unrelated aspects. Assessing maternal stress levels would not provide direct insight into fetal well-being. Measuring fetal heart rate variability serves as an indicator of fetal health but is distinct from evaluating the acid-base status provided by the pH test. Finally, determining maternal blood type compatibility is important for managing potential hemolytic disease of the newborn but is not related to immediate fetal assessment during labor. Thus, the fetal scalp pH test specifically plays a critical role in assessing fetal health during labor.