A client at 36 weeks' gestation feels lightheaded while measuring fundal height. What is the most likely cause of this symptom?

The symptom of lightheadedness experienced by the client at 36 weeks' gestation is most likely due to compression of the vena cava, a condition sometimes referred to as supine hypotensive syndrome. As the uterus grows larger during pregnancy, it can exert pressure on major blood vessels, particularly when the patient is in a supine position. This compression can impede blood return to the heart, resulting in reduced cardiac output and symptoms such as lightheadedness or even fainting.

The timing of the symptom, given the advanced stage of pregnancy, reflects how significant the size of the uterus can be in affecting blood circulation. It is important for pregnant individuals to avoid lying flat on their backs, especially later in the pregnancy, to help alleviate this compression and improve blood flow.

While dehydration, anemia, and low blood sugar can also lead to feelings of lightheadedness, they are less likely to be the primary cause in this scenario. Dehydration may cause lightheadedness but usually is accompanied by other signs (such as dry mouth or decreased urine output), and the client’s hydration status is not assessed in this context. Anemia can lead to dizziness, but specific symptoms and laboratory confirmation are needed to assess this. Low blood sugar can cause light