From my understanding "not always". I had HELLP with my first pregnancy. I was put on bedrest at 35 weeks because I had ONE borderline high blood pressure reading. As I was on bedrest I was monitored for liver enzymes and 24 hour urine collections. Suddenly I had HELLP. I am a completely healthy person, work out, eat well, normal weight, etc.
Me (29) DH (30) #1-Olivia Caetlyn-9-28-09-9-28-09, 23+2 wks, emergency classic c-section, class I HELLP, IUGR #2- Lucas Oliver (rainbow baby)- April 2011, 36+2 wks, HELLP and pre-e free! (lovenox and LDA pregnancy) #3-Matthew, late October 2012...mostly normal, 37 wks, (lovenox and LDA again) My blog: http://www.butterflies-and-rainbows.blogspot.com/
Not in my case either. I think it is more common to find an underlying condition in women who had early or especially severe PE/HELLP, but I have never seen anything that suggests that most/many women with HELLP have an underlying condition.
Daughter born April 2009 at 35 weeks due to Class 1 HELLP