Damned if I know...
2006-07-21 09:15 pmGood article on preeclampsia in this week's New Yorker.
Karumanchi believes that women who have closely spaced pregnancies have a lower risk of developing preeclampsia because the blood vessels in their uteruses don't have a chance to return to their pre-pregnancy shape. They are able to supply relatively robust amounts of blood to the fetus early in pregnancy, thus minimizing the likelihood of oxygen deprivation and the need for the placenta to produce soluble FLT. "People in the field say that the uterine vessels can be thought of as a panty-hose stocking," Karumanchi said. "Once you expand them, it takes a long time for them to return to their original shape."
Which may explain some things. Sorry -- I think I need to crawl back into my hole and go back to being a geek now.