High bp is an interest to me because I had it with both my pregnancies and nurses kept telling me that I had pre-eclampsia. I had to keep explaining that it is not the same thing, while thinking, "these people are responsible for my healthcare?"
Anyway, here are some of the articles that I found a few months ago when researching this issue. Hope they are helpful.
1. Atallah AN, Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems
Calcium supplementation appears to be beneficial for women at high risk of gestational hypertension and in communities with low dietary calcium intake. Optimum dosage requires further investigation
2. Niromanesh S, Supplementary calcium in prevention of pre-eclampsia. Int J Gynaecol Obstet 2001 Jul;74(1):17-21
METHODS: Thirty pregnant women at high risk of developing pre-eclampsia were randomized to 2 g of daily calcium and placebo. The inclusion criteria were positive rollover test, having at least one risk factor for pre-eclampsia, between 28 and 32 weeks of pregnancy, and blood pressure less than 140/90 (mm Hg). RESULT: A sevenfold reduction in the occurrence of pre-eclamsia were seen among the calcium group compared with the placebo group (7 out of 15 developed pre-eclampsia in control group vs. 1 out of 15 in calcium group, P=0.014). No major effect on pregnancy induced hypertension was seen but the onset of hypertension was delayed 3 weeks in the calcium group. CONCLUSION: Calcium supplementation is beneficial for preventing pre-eclampsia among Iranian women at high risk of developing pre-eclampsia.
3. Ziaei S. Eur J The effect of garlic tablet on plasma lipids and platelet aggregation in nulliparous pregnants at high risk of preeclampsia. Obstet Gynecol Reprod Biol 2001 Dec 1;99(2)01-6
The administration of 800mg/day of Garlet (Garlic tablet) during the third trimester of pregnancy was effective in reducing the occurrence of hypertension alone, but it was not effective in preventing of preeclampsia.
4. There is an article about treating hypertension in pregnancy with prepared rhubarb, but the article is in chinese so I don't know how the rhubard is prepared.
5. Adam B, Magnesium, zinc and iron levels in pre-eclampsia Matern Fetal Med 2001 Aug;10(4)46-50
Our results suggest that low cellular magnesium levels in women with pre-eclampsia may contribute to the development of hypertension in these patients, and that the measurements of plasma zinc and serum iron concentrations are of doubtful clinical value in the management of pre-eclampsia. Abstract does not state how much magnesium should be supplimented.
6. Saeed SA, Not pre-eclampsia. J R Soc Med 2001 Jul;94(7):351-3.
This article looks interesting just for its title. I don't have access to the abstract now, but I'm putting it here so I can remember to look it up later. If this article is about high bp not automatically meaning pre-e, then I may carry a copy with me to every prenatal appointment!