Which method is NOT effective in preventing preeclampsia?

Bed rest is not considered an effective method in preventing preeclampsia. While traditionally, bed rest was often recommended for various pregnancy complications, recent evidence does not support it as a preventive measure for preeclampsia. Studies have shown that there is no significant benefit in terms of reducing the incidence of preeclampsia or its associated risks through prolonged bed rest.

In contrast, calcium supplementation has been associated with a reduced risk of preeclampsia, particularly in women who have low dietary calcium intake. Aspirin therapy, particularly low-dose aspirin, has shown efficacy in lowering the risk of developing preeclampsia in high-risk populations. Fish oil supplementation is also being researched for its potential benefits, with some studies indicating it may help with reducing the incidence of preeclampsia, though the evidence is less definitive compared to calcium and aspirin.

Thus, bed rest does not provide a proven preventative effect against preeclampsia compared to the other options listed.