The major aim of this study is to examine the salt sensitivity of the ambulatory blood pressure in women with a history of severe preeclampsia (< 34 weeks gestation) compared with women with no history of pregnancy-related hypertensive complications. We plan to recruit 20 non-menopausal women with a history of severe preeclampsia, and 20 age, parity, race- matched premenopausal women as controls. The study has a case control randomized design. The salt sensitivity of the ambulatory blood pressure is defined as an increase of ≥4 mmHg in 24h ambulatory blood pressure on a high sodium diet. The high sodium diet is obtained by adding capsules of 6gr of NaCl/ day in the usual diet.