A recent review of the literature on thrombophilia and adverse pregnancy outcome reveals contradictory findings. There are retrospective and prospective studies that recommend testing for genetic and acquired markers of thrombophilia for those with the enumerated adverse pregnancy outcome. Based on our review, routine screening for thrombophilias in women with a history of adverse pregnancy outcome (preeclampsia, abruptio placenta, intrauterine growth restriction, and fetal loss) is not justified. Based on data from observational studies and few randomized trials with inadequate number of subjects, there is consensus that women with true antiphospholipid antibody syndrome should receive low-dose aspirin plus adjusted-dose heparin in subsequent pregnancies. Some authors also recommend heparin prophylaxis in subsequent pregnancies in women with genetic thrombophilia with previous adverse pregnancy outcome. However, this recommendation is not based on randomized trials. Hence, a randomized double-blind, controlled trial is urgently needed to evaluate the benefit of heparin during pregnancy in women with a history of adverse pregnancy outcome in association with genetic thrombophilia.