Which of the following is an important aspect of positioning pregnant clients during a massage?

Maintaining a side-lying position is often recommended for pregnant clients during a massage due to several important factors related to safety and comfort. In this position, the weight of the growing uterus is alleviated from the major blood vessels, particularly the inferior vena cava, which can become compressed when a pregnant person lies flat on their back. This compression can lead to reduced blood flow and oxygen to the fetus, making the side-lying position a safer choice.

Additionally, positioning a pregnant client on her side can help reduce discomfort and pressure on the lower back and pelvis, allowing for a more relaxing and beneficial massage experience. This position supports proper alignment and can also enhance relaxation by alleviating strain on the body's ligaments and supporting structures.

While other positions, such as seated or lying face down, might seem feasible, they do not promote the safest or most comfortable experience for pregnant clients, especially as the pregnancy advances.