Novel technique can improve quality of animal embryos produced in vitro Researchers at a startup supported by FAPESP have developed a material that mimics conditions in the uterus and could result in a 32% rise in bovine embryo production. Raquel Zaneti Puelker, a veterinarian who specializes in bovine in vitro embryo production, used to ask herself this question all the time. “A great deal of progress has been made, but there are still deficiencies in the conversion of embryos produced in vitro into pregnancies. Embryos produced in vitro are highly sensitive to cryopreservation, while those produced in vivo are much less so. Between 30% and 60% of in vitro embryos are converted into pregnancies, compared with up to 80% for in vivo embryos.