I assume pitocin can raise your bp just like labor can raise your bp (and the preeclampsia biology Caryn describes is both fascinating and a scary reminder of why labor and the first 24 hours after birth are especially dangerous) - but I'm concerned about your statement "And that can actually lead to many of the same things preeclampsia causes."
That doesn't seem accurate to not-a-doc me. Here's a study that lists complications of preeclampsia, I'm not aware that hypertension from effort (I'm thinking hard exercise or weight lifting as a comparison?) has any similar bad outcomes:http://www.ncbi.nlm.nih.gov/pubmed/17983486
CONCLUSIONS: (1) The morbidity of severe complications from high to low are: placental abruption, DIC, induced cardiopathy, renal failure, cerebro vascular accident and HELLP syndrome. (2) The main causes of mortality for gravida and puerperant are: cerebro vascular accident, HELLP syndrome, DIC and induced cardiopathy. (3) The major complications harmful to perinatal newborns are in the order of: placental abruption, HELLP syndrome, DIC, renal failure, cerebro vascular accident and induced cardiopathy.
My understanding is that the blood pressure increases and the other complications of preeclampsia are symptoms of the underlying pregnancy dysfunction.
I can "hear" you still trying to wrap your mind around all this, you're doing good, keep reading! If you can find more specifics about why pitocin would be similar to preeclampsia I'm more than happy to learn more! Oh - and I can't find it right now, but I'm sure there's some other Expert responses about the 30/15 increase, and I'm pretty sure there's one about pre-hypertensives and hitting the 140/90... have fun in the Ask the Experts archives and let us know what you find! Also, keep in mind that the 140/90 is a *research definition* - women can and do get sick at lower pressures, with and without protein, with and without bad labs. The research definitions are very important for research, but in practice, doctors have to be more flexible! Our Experts say over and over that "doctors treat people, not diseases".