Many biomaterial-based delivery technologies–such as inorganic, polymeric, and lipid-based nanoparticles, as well as chemically-modified drugs–have successfully navigated the pathway from invention to the clinic for therapeutic applications including cancer, genetic disorders, autoimmune diseases, and imaging. Although, the field has yet to witness the translational potential of these technologies in the context of obstetric disorders during pregnancy. In this chapter, we discuss recent preclinical research advances at the interface of biomaterials science and placental biology. First, in an effort to highlight the opportunity to repurpose clinically-approved technologies toward obstetric applications, we provide an overview of various biomaterial-based delivery technologies and their current regulatory status. We then discuss efforts to engineer delivery technologies to interface with the placenta in several ways: (i) to enable delivery of a therapeutic payload to the placenta itself, (ii) to harness the placenta as a biological barrier and enable drug retention in maternal circulation, or (iii) to facilitate transplacental drug transport to enable therapeutic payload delivery to the fetus in utero. Finally, we examine the existing literature to date that explores the therapeutic efficacy of these engineered biomaterial-based delivery technologies to treat obstetric conditions such as pre-eclampsia, fetal growth restriction, and gestational trophoblast disease.