Which of the following warning signs during pregnancy should prompt a client to notify their health care provider?

Visual disturbances during pregnancy can indicate potential complications that may require immediate medical attention. This symptom can be associated with serious conditions such as preeclampsia or eclampsia, which involve elevated blood pressure and can adversely affect both the mother and the fetus. Changes in vision, such as blurriness, seeing spots, or sudden loss of vision, should always be evaluated by a healthcare provider to rule out these serious conditions.

Low energy, while a common experience in pregnancy, is typically not a warning sign of a serious problem unless accompanied by other concerning symptoms. Shortness of breath may also occur in later stages of pregnancy due to physical changes but is usually not a standalone warning sign unless it is severe or sudden. Frequent headaches can occur for various reasons during pregnancy, such as hormonal changes or tension, but do not necessarily indicate an urgent medical issue unless they are severe, persistent, or accompanied by other alarming symptoms such as visual changes.