Kristina, this is straight from Pounds & Inches..
" When the blood pressure is abnormally high, and provided there are no detectable renal lesions, the pressure drops, as it usually does in pregnancy. The drop is often very rapid, so rapid in fact that it sometimes is advisable to slow down the process with pressure sustaining medication until the circulation has had a few days time to adjust itself to the new situation. On the other hand, among the thousands of cases treated, we have never seen any untoward incident which could be attributed to the rather sudden drop in high blood pressure.
When a woman suffering from high blood pressure becomes pregnant her blood pressure very soon drops, but after her confinement it may gradually rise back to its former level. Similarly, a high blood pressure present before HCG treatment tends to rise again after the treatment is over, though this is not always the case. But the former high levels are rarely reached, and we have gathered the impression that such relapses respond better to orthodox drugs such as Reserpine than before treatment."
For me, back in 2005 I weighed 320 lbs. My blood pressure was controlled by meds but still on toward the upper limits. Since losing weight, both through lapband and now this diet, my blood pressure is on the low end of normal.