Running throughout pregnancy: effect on placental villous vascular volume and cell proliferation

Many studies have documented that placental development is altered by a variety of environmental factors which alter placental bed blood flow and/or oxygen delivery. One of these is sustained weight-bearing exercise. The purpose of this investigation was to examine the effects of running throughout pregnancy on villous vascular development and cell proliferation by testing the null hypothesis that continuing a regular running regimen throughout pregnancy has no effect on villous vascular volume or cell proliferation at term. Accordingly, placentae of 11 healthy runners with uncomplicated pregnancies were matched by placental weight, maternal diet and birth weight with those of 11 healthy controls and examined using systematic random sampling and point counting of placental tissues stained immunohistochemically with either an endothelial (CD 31, PECAM-1, endoCam) or a proliferative (Ki-67, MIB-1) marker. The placentae of the runners had greater villous vascular volumes in both absolute ( 77±20 cm 3 versus 47±18 cm 3 , p