VENOUS DISTENSIBILITY DURING PREGNANCY DETERMINED BY GRADED VENOUS CONGESTION

The increase in volume of the human calf and forearm during pregnancy resulting from graded venous congestion was measured plethysmographically in the raised leg and forearm of 10 recumbent subjects during and after pregnancy. Normal pressure volume curves were determined and the alterations in this curve over the various stages of gestation were presumed to indicate an alteration in the distensibility of the capacity blood vessels. This distensibility increased with the progression of pregnancy in both the forearm and the calf particularly after the 30th wk of pregnancy. The distensibility appeared to return to below the 10 wk gestation level at the 8th postpartum week. The increase in distensibility was greater in the calf than in the forearm although both were significantly increased.