The purpose of this study is to investigate whether endothelial dysfunction, as assessed by elevated cellular fibronectin (cFN), in women with preeclampsia is associated with an increased risk of preterm and/or small-for-gestational-age (SGA) births. Maternal plasma cFN was measured by enzyme-linked immunosorbent assay in samples collected at admission to delivery in 605 normotensive women, 171 women with transient hypertension, and 187 women with preeclampsia. Logistic regression was used to estimate the risk for preterm delivery, SGA, or both. Elevated cFN in women with preeclampsia was associated with an increased risk of both preterm and SGA births (odds ratio, 3.0; confidence interval [CI], 1.0-8.7) compared with women with preeclampsia without elevated cFN. The risk of preterm birth was 14.7-fold higher (CI, 8.1-26.7) and the risk of SGA was 6.8-fold higher (CI, 3.5-13.1) in women with preeclampsia, hyperuricemia, and elevated cFN compared with normotensive women. Elevated cFN is prevalent among women with preeclampsia and identifies women at increased risk of preterm delivery and SGA.