From what I have read here, having autoimmune disorders or clotting factor disorders do put you at higher risk for PE. I'm so sorry for your loss. Did you continue the heparin and/or baby asprin throughout your pregnancy? I don't know anything specific about AS, but if you would like more information I would suggest running a search on this website (specifically the "ask the experts" section). You can also ask this question in the "ask the experts" section but know that those doctors donate their time and are quite busy so it may take some time to get a full response.
As to whether or not to try for another baby, that is a decision that you have to make. There are many here who have faced this same decision. I would definately suggest a second opinion by a perinatologist/maternal fetal specialist. You can find one that specializes in PE here:
Welcome to the PF and feel free to ask any more questions you may have! Hope this helped some!
DH Britton (27)
Emma Margaret (03/02/03) 37 weeks from PIH & oligo