Anatomical and physiological changes in the venous system of lower limbs in pregnant women and findings associated with the symptomatology.

Purpose: Quantify the volume and diameter of veins in the lower limbs of primigravidae and associate the presence of venous signs and symptoms with the vascular measurements.

Methods: A cross-sectional study assessed 64 lower limbs of 32 healthy women of whom 16 were primigravidae between 22 and 36 weeks pregnant, and 16 nulligravidae. The women were submitted to physical assessment, air plethysmography and vascular ultrasound. The volumes and diameters of the main veins in the lower limbs were compared between pregnant and non-pregnant women. In the group of pregnant women, the attempt was also made to associate such measurements to the presence of vascular signs and symptoms.

Results: The average venous volume of the lower limbs (110.1 ± 30.2 and 94.7 ± 27.3 mL; p = 0.036), as well as the diameters of the common femoral (12.72 ± 2.27 and 10.14 ± 1.24 mm; p < 0.0001), saphenous (4.81 ± 1.15 and 3.55 ± 0.98 mm; p < 0.0001) and popliteal (6.87 ± 1.68 and 5.36 ± 1.07 mm; p < 0.0001) veins were, respectively, greater in the pregnant women compared with the control group. In pregnant women with venous stasis symptoms, a venous diameter of the saphenous vein compared to those without no symptoms (5.05 ± 1.19 and 4.09 ± 0.70 mm; p = 0.011) was noted.

Conclusions: Anatomical and functional changes in the venous system during pregnancy were detected by the air plethysmography and the vascular ultrasound in primigravidae. In pregnant women, the presence of venous stasis symptoms found an anatomical and functional substrate detected in the differences in diameter of the saphenous vein.