look into magnesium supplementation. apparently vets link pre eclampsia in animals to low magnesium and its a known way to treat it.
and i think that when pre eclampsia is really bad in the last trimester, don't docs sometimes give intravenous magnesium??
my naturopath has me on extra magnesium at the moment as i have a family hx of preeclampsia, i must admit i havent been so good at taking it though..