Registered Nurse Certified in Maternal Newborn Nursing (RNC-MNN) Practice Test

The left lateral position is recognized for its beneficial effects on uteroplacental blood flow during labor. By positioning the mother on her left side, gravity helps to minimize pressure on the inferior vena cava, a large vein that returns blood from the lower body to the heart. When this vein is compressed — as can occur when a pregnant woman lies supine (on her back) — it can impede venous return, decrease cardiac output, and subsequently reduce the blood flow to the uterus and placenta.

Thus, adopting the left lateral position supports optimal blood flow to the fetus by facilitating better circulation. This can help improve oxygenation and nutrient delivery, which are crucial for fetal well-being during labor. The avoidance of supine positioning is particularly important in late pregnancy where the weight of the uterus can significantly affect venous return, making the left lateral position the preferred choice for enhancing uteroplacental circulation during labor.