What does a Category 3 tracing typically include?

A Category 3 fetal heart rate tracing is identified by the presence of abnormal patterns that indicate potential fetal compromise. Specifically, it typically includes absent variability accompanied by recurrent variable decelerations. This indicates that the fetus may not be receiving adequate oxygen or may be experiencing stress, leading to concerning signs in the heart rate pattern.

The absence of variability suggests that the heart rate is not responding appropriately to the fetus's movements or conditions, which is a critical warning sign. Recurrent variable decelerations are abrupt drops in heart rate that occur with changes in uterine contractions, reflecting possible umbilical cord compression. In this context, both absent variability and recurrent decels highlight a significant risk of hypoxia and necessitate immediate clinical evaluation and intervention.

Other patterns in the options, such as normal variability with occasional late decelerations or moderate variability with prolonged decels, do not meet the criteria for Category 3 and are often seen in more stable situations. Additionally, a baseline stable fetal heart rate with early decelerations generally does not indicate a severe risk to the fetus. Hence, the combination of absent variability and recurrent variable decelerations distinctly characterizes Category 3 tracings.