What observation during the first 24 hours postpartum supports a diagnosis of endometritis?

The presence of abdominal tenderness and chills during the first 24 hours postpartum is indicative of endometritis, which is an infection of the endometrium (the inner lining of the uterus) that can occur after childbirth. Abdominal tenderness suggests inflammation or infection in the uterine area, and chills are a common systemic response to infection, signaling the body's attempt to fight off pathogens. This combination of symptoms reflects an inflammatory process that often accompanies endometritis, making it a key observation in supporting the diagnosis.

In contrast, normal lochial flow would not indicate endometritis, as lochia typically becomes lighter and less odorous, and is expected in a normal postpartum period. A high energy level and positivity might suggest a well-adjusted and healthy postpartum period, which is not consistent with the symptoms of an infection. Lastly, stable vital signs usually indicate that there is no significant infection or other complications present, whereas endometritis is often associated with abnormal vital signs like elevated temperature or tachycardia.