Related Experiment Video
Updated: May 10, 2026

Assessment of Maternal Vascular Remodeling During Pregnancy in the Mouse Uterus
Published on: December 5, 2015
Anatomical factors causing oedema of the lower limb during pregnancy
Brion Benninger1, Taylor Delamarter
1Northwest Oregon Health & Sciences University, Lebanon, OR, USA. bbenninger@westernu.edu
Background:
The objective of this study was to investigate the morphology of the common iliac artery and vein (CIA&V) comparing right and left sides in females versus males. Pregnant women favour lying on one side at rest and during sleep. The reason for this may be due to the morphology and orientation between the CIA&V. Virtually all women during their pregnancy suffer from lower limb swelling. This study provides an anatomical explanation for the propensity to lie consistently on one side, for lower limb swelling, and offers prevention measures.
Materials And Methods:
A literature search was conducted on anatomical texts, atlases, journals, and websites regarding the morphology and orientation of the right and left CIA&V, lower limb oedema, and sleeping positions during pregnancy. Measurements from 15 dissected cadavers were conducted on the right and left CIA&V.
Results:
The literature search revealed very limited studies on the morphology and orientation of the right and left CIA&V with no studies relating this orientation to lower limb oedema or sleeping positions during pregnancy. Cadaver dissection revealed a relatively direct anterior to posterior orientation left CIA&V and an oblique lateral to medial right CIA&V.
Conclusions:
This study suggests an explanation of why women lie on their left side when resting and sleeping during the third trimester due to the clinically relevant anatomy between the CIA&V.
Related Concept Videos
Veins of Lower Limbs
Formed by the union of the medial and lateral plantar veins, the posterior tibial vein, rising through the calf muscle, assimilates the fibular vein. The anterior tibial vein, a superior extension of the foot's dorsalis pedis vein, merges with the posterior tibial vein at the knee,...
Varicose Veins I: Introduction
Pulmonary Edema II: Pathophysiology
Cerebral Edema l: Introduction
Venous Thrombosis IV: Nursing Management
Hormonal Regulation

