Lumbar pillow placement for left uterine displacement in pregnant women: a randomized, controlled trial

The most effective lumbar pillow placement, which best enables left uterine displacement and does not interfere with cardiopulmonary resuscitation, is unclear. We aimed to examine whether changing pillow placement positions affects the degree ofpelvic and thoracic tilt for left uterine displacement in full-term pregnant women.

This prospective randomized, controlled trial included 38 healthy pregnant women at >37 weeks'gestation. The primary outcome was pelvic tilt (angle). The secondary endpoints werehemodynamic changes and thoracic tilt. The patient was placed in the supine positionand with left uterine displacement using the following methods in random order: the superior anterior iliac spine coinciding with the lower edge of the pillow (U), the middleof the pillow (M), the upper edge of the pillow (L), or tilting the bed 15° to the left without pillow placement (B). Pelvic tilt, blood pressure, heart rate, and thoracic tilt were measured and compared for each pillow position.

Patient background, blood pressure, and heart rate did not differ among the groups. Pelvic tilt was greater in groups M/L/B than in group U. Thoracic tilt was greater in group B than in all other groups and greater in group U than in groups M/L.

Aligning the pillow's center/upper edge with the right iliac spine optimizes pelvic tilt and minimizes the tilt of the rib cage. Further study is required to determine if this method contributes to effective left uterine displacement during surgery or cardiopulmonary resuscitation.