What is a common reason for performing an ultrasound in the first trimester?

Performing an ultrasound in the first trimester primarily aims to determine fetal viability, which is crucial for assessing whether the pregnancy is progressing normally. The first trimester, encompassing the first 12 weeks of pregnancy, is a critical time for development, and monitoring the presence of a heartbeat is one of the earliest indicators of a healthy pregnancy.

During this period, healthcare providers often use ultrasound to confirm intratuterine pregnancy and rule out ectopic pregnancies, which can pose significant risks. Establishing fetal viability through ultrasound helps to reassure the patient and guide further prenatal care.

The other options relate to different aspects of pregnancy monitoring: assessing amniotic fluid levels is typically done later in pregnancy, usually in the second or third trimester; checking fetal position is usually reserved for later stages when the fetus begins to engage in the pelvis; monitoring contractions is more relevant during labor, particularly in the third trimester when the body prepares for delivery. Thus, the focus of first-trimester ultrasounds is primarily on establishing fetal viability.