Preeclampsia is characterized by hypertension, dyslipidemia, and increased systemic inflammatory response and has been associated with an increased maternal risk of cardiovascular disease later in life. Low-grade chronic inflammation is a risk factor for cardiovascular disease. This study examined changes in inflammatory markers prospectively during pregnancy, the current inflammatory status of women who had a pregnancy complicated by preeclampsia 20 years previously against matched controls, and the association between inflammatory genes and risk of preeclampsia in a case (n=106) control (n=212) study. In control pregnancies (n=34), mean interleukin-10 (IL-10) levels increased 38% (P=0.012) and tumor necrosis factor-alpha (TNF-alpha) by 33% (P=0.024) between the first and third trimesters. The mean preeclampsia group IL-10 and TNF-alpha rose by 43% (P=0.013 and P=0.0065, respectively) from the first to the third trimester. In women with preeclampsia only, plasma IL-6 increased from the first to the third trimester (1.66 [2.04] to 2.94 [2.47] pg/mL; P=0.0004). Twenty years after the index pregnancy, women who had had preeclampsia demonstrated significantly higher IL-6 to IL-10 ratio (3.96 [6.07] versus 2.12 [1.89]; P=0.034) compared with a healthy index pregnancy 20 years previously, that persisted after adjustment for smoking and current body mass index. The IL-1beta (C-511T), IL-6 (G-174C), TNF-alpha (G-308A), E-selectin (S128R), intercellular adhesion molecule-1 (K469E), and C-reactive protein (C1059G) polymorphisms were not associated with risk of developing preeclampsia. In conclusion, preeclampsia is associated with short- and long-term changes in inflammatory status.