Abstract
The blood flow in the lower legs of 68 primi-gravidae was examined plethysmographically, by which a measure of mainly the muscle flow was obtained. The subjects were divided into three groups according to duration of pregnancy, and the blood flow at rest and during reactive hyperaemia was recorded. The periods of pregnancy were 9–13 weeks (Group A), 15–22 weeks (Group B) and 37–42 weeks (Group C). Subjects in Group A were examined 1 day, 2 weeks and in a few cases 8 weeks after abortion in addition to examination during pregnancy: subjects in Groups B and C were examined 2 weeks after abortion and delivery respectively. The blood flow at rest during pregnancy, expressed in ml/min × 100 ml tissue was lower in Group C than in Groups A and B. During reactive hyperaemia the blood flow did not differ significantly between the three groups. In early pregnancy the muscular blood flow does not seem to increase in comparison with the nonpregnant state. The increased cardiac output during early pregnancy thus does not seem to pass through the muscles of the limbs. During the latter half of pregnancy resting blood flow measured with the subject in the supine position decreases, which is contrary to earlier reports.