Which condition is associated with a high fetal heart rate (FHR) due to lack of oxygen?

A high fetal heart rate (FHR), often characterized as tachycardia, can be a response to inadequate oxygen, leading the fetus to attempt to compensate for the hypoxic condition. Chronic fetal distress is a state where the fetus experiences ongoing stress and lack of sufficient oxygen over time, which can result from various maternal or placental issues. As the fetus seeks to maintain adequate tissue oxygenation, an increase in heart rate is a physiological response.

In chronic fetal distress, the persistent lack of oxygen can stimulate the fetal autonomic nervous system, leading to an elevated heart rate as a compensatory mechanism. This is especially relevant in situations where placental function is compromised, causing reduced oxygen delivery to the fetus.

Understanding this mechanism is important for monitoring fetal well-being. The other conditions listed do not primarily cause an elevated FHR due to oxygen deficiency. For instance, fetal heart block may result in a slower heart rate, myocardial depression generally refers to a decrease in heart rate and contractility, and although intrauterine growth restriction might involve some degree of fetal compromise, it does not necessarily correlate directly with a chronic elevation of FHR in response to hypoxia.