Well no one really knows. Since its not be determined yet what causes PE nor what causes the BP to rise in pre eclamptic woman there is really no answer.
For the most part, it is beleived by some that the rise in BP is a symptomn of something else going wrong or not working. Thus, like many other conditions or like something like the flu, all you can do is try to treat the symptons and ride it out.
One thing that would be helpful is to know what your baseline BP is. If its the 130/77 you really don't have that much to worry about unless it starts to rise consistantly higher and higher. Remember that your BP can fluctuate by a number of points throughout the day. Thus you may get a wide variety of of readings throughout the day, and will move depending on stress levels, anxiety, foods you have eaten, etc...
In order to truely track your BP you need to take and track your BP several times, a day. To do this you need to take 5 minutes to totally relax, then take your pressure. You should take it at the exact same times everyday and in the same arm every time. For example you might take it at 7am, 10pm, 2pm, 7pm, 10pm in your right arm over 3 days. You also need to track whats going on in your day. This will show you how the things in your day or the foods that you eat affect what happens to your BP.
In my first pregnancy my BP started at like 125/68 and slowly rose a few points every visit until it hit 140/80 at around 26 weeks. In my second pregnancy it stayed about 130/75-80 for most of the pregnancy and then started spiking up into the 140/90 but at the same time I was also having many other symptomns like seeing spots, blurred vision, weight gains/swelling, etc..
Mommy to Alex and Mason