Which of the following best describes a symptom of perinatal anxiety?

The symptom that best describes perinatal anxiety is excessive worry about health and the baby. This form of anxiety is characterized by persistent, often uncontrollable concerns related to one’s own health and the health of the baby during the perinatal period. Such worries may encompass fears of complications during pregnancy, the baby's development, and their future well-being.

In contrast, excessive joy and excitement do not align with anxiety; rather, they reflect positivity typically associated with anticipation and happiness about the upcoming birth. Strong self-esteem is unrelated to anxiety and suggests confidence, which can be diminished in anxious individuals. Rapid weight gain, while it can occur during pregnancy, is a physiological condition that does not specifically indicate anxiety and may be influenced by various factors such as diet, hydration, and hormonal changes. Therefore, the correct answer pinpointing a symptom of perinatal anxiety is the excessive worry about health and the baby.