Llurba E, Bella M, Burgos J, et al. - The effectiveness of low-molecular-weight heparin (LMWH) in the prevention of preeclampsia (PE), intrauterine growth restriction (IUGR), fetal death, and abruptio placentae was examined in women classified as high risk based on their medical history and in women selected by first trimester screening of PE. In this multicenter, randomized, open-label, parallel controlled trial, women without thrombophilia between 6.0 and 15.6 weeks of gestation were randomly assigned to receive no intervention or LMWH until the 36th week of gestation. Among 278 included women, 134 were randomly allocated to receive LMWH and 144 received no intervention. Outcomes revealed no correlation of receiving LMWH with reduction in the incidence of placenta-mediated complications, either in women with previous adverse obstetric history without thrombophilia or in women selected by first trimester screening for PE. Based on these outcomes, the use of LMWH alone cannot be recommended in women at risk of placental complications.