placental abruption

[JOYWAWER]

In January 2007, I found out that I was pregnant, afew wks later I started spotting and having abdominal cramping. I had a trans-vaginal ultra-sound which detected nothing. Baby was well attached no bleeding in the sac,good heart beat etc etc. I went through several medications due to severe hyper-emesis and lost about 15 pounds. At 20 weeks the nausea had subsided which was a big relief to me because I could now eat. My ultrasound sound at 20 wks showed that I was having a girl and that every thing was okay. At 25 weeks I woke up one morning with severe lower back pain and some bleeding, I got to the hospital but by the time I got there my daughter had already passed away! When she was born they found a large blood clot adhered to the placenta and my doctor at the time believed I also had a placental abruption. I have never been at peace with this, I am currently trying to concieve and im just wondering if it is possible that I may have a blood clotting disorder or was the blood clot on my placenta trying to repair the slowly rupturing placenta? Is there such a thing as genetic placental disorders? the reason I ask is because my sister also had a baby that was born prematurely due to placental insufficiency. Any help would be greatly appreciated!