Updated publication reference for PubMed record(s): 28831049. Hypoxia-related pregnancy complications increase the risk of disease in the child in later life. No prevention is available. Previously we noted that a trophoblast barrier, an in vitro model of the placenta, reacted to oxidative stress by secreting factors that damage neighbouring cells. Application of mitochondrion-targeted antioxidant MitoQ prevented this. Here we tested the effects of MitoQ-bound nanoparticles on trophoblast barriers and in a rat model of gestational hypoxia.A single dose of MitoQ-nanoparticles, administered maternally before a hypoxic episode, reduced oxidative stress in the placental barrier without reaching the fetus and prevented changes to birthweight. MitoQ-nanoparticles further suppressed damaging signalling from the placental barriers. Altered signalling molecules in the fetal plasma and in conditioned media from rat placenta included changes to proteins with relevance to cardiovascular disease. We suggest as a future possibility, treatment of the placenta to prevent disease in the offspring in later life.