Which of the following factors could necessitate fetal heart monitoring?

Fetal heart monitoring is particularly necessary in high-risk pregnancies or in situations where complications arise. In these instances, continuous assessment of the fetal heart rate can provide crucial information about the well-being of the fetus, allowing healthcare providers to identify potential distress or issues early on. Factors such as preexisting maternal health conditions, pregnancy-induced hypertension, or gestational diabetes may place the pregnancy at a higher risk, necessitating closer monitoring of the fetus's condition through techniques such as electronic fetal monitoring.

Routine prenatal care generally does not require the same level of ongoing monitoring unless specific risk factors are present. Maternal obesity can be a factor that complicates pregnancies but on its own does not automatically demand intensified fetal heart monitoring unless it is linked to other issues. Fetal viability confirmation typically occurs in early pregnancy through ultrasound and may not require ongoing heart monitoring unless there are additional concerns or risk factors that arise later. Thus, the need for fetal heart monitoring is most aligned with the presence of high-risk pregnancies or associated complications.