Why is positioning in the left lateral recumbent position recommended for third-trimester bleeding?

Positioning in the left lateral recumbent position during third-trimester bleeding is particularly important because it improves venous return. This position helps to alleviate pressure on the inferior vena cava, a large vein that carries blood from the lower body back to the heart. When a pregnant person is in a supine position (lying flat on their back), the weight of the uterus can compress the inferior vena cava, reducing blood flow to the heart and potentially leading to decreased cardiac output and hypotension. By positioning the individual on their left side, blood flow is enhanced, which is crucial for maintaining maternal and fetal circulation during such an emergency.

While comfort is important, especially in labor, and while visualization of the perineal area can be helpful for assessment, these factors do not primarily address the critical need for maintaining proper blood flow and perfusion in situations of third-trimester bleeding. Contractions can be painful, but positioning specifically in the left lateral recumbent position is not intended to relieve discomfort directly, making the focus on venous return the most relevant reason for this recommendation.