Effects of Glyphosate Exposure on Reproductive Health: A Systematic Review of Human, Animal and In-Vitro Studies

Glyphosate is the most widely used herbicide in the world. We examined whether and how human populations exposed to glyphosate at any age are at risk of developing reproductive health effects. Protocol was developed following the recommendations of the PRISMA guidelines. Original research published in indexed journals was included with direct and indirect exposure to glyphosate, from any country/region, without publication year restriction, in English or Spanish. We included observational studies in humans, as well as experiments in vitro or in animal models. Studies were searched in four databases. The scoring assignments were based on the guidelines for conducting systematic reviews in the development of toxicity factors. The findings on the agent and exposure assessment were retrieved and summarized in a narrative synthesis. After eliminating duplicates among the identified articles and reviewing the inclusion and exclusion criteria, 80 were included in the narrative synthesis, i.e., 20 human studies, 44 animal studies, and 16 using in vitro models. This review shows strong experimental evidence, in animal models and in vitro studies, of glyphosate toxicity in reproduction and development as well as related metabolic and disease consequences. Several of these studies show significant health consequences for mothers, fetuses, and offspring, even several generations after exposure. Human studies, in contrast, are scarce and controversial. Nevertheless, we believe that the evidence is sufficient to, under the precautionary principle, define policies to prevent exposure of women, their partners, and their children to glyphosate.