National Dental Assisting Examining Board (NDAEB) Practice Exam

What condition might a patient in their third trimester of pregnancy experience while lying in a supine position in the dental chair?

1. Dizziness

2. Hypotension

3. Nausea

4. Fatigue

The correct answer is: Hypotension

During the third trimester of pregnancy, a patient lying in a supine position can experience hypotension, particularly due to the compression of the inferior vena cava by the enlarged uterus. This condition is commonly referred to as "supine hypotensive syndrome." When the pregnant patient is in a supine position, the weight of the uterus can obstruct blood flow returning to the heart, resulting in decreased venous return, lower cardiac output, and subsequent drops in blood pressure. It is vital for dental professionals to be aware of this phenomenon and to adjust the position of the patient accordingly, often by tilting the chair to the left side or placing the patient in a semi-reclined position. This adjustment alleviates pressure on the major blood vessels, helping to maintain adequate blood flow and blood pressure, thereby ensuring the safety and comfort of the patient during dental procedures.