Usually, this type of study is conducted on mice, which are easier to come by and carry less ethical considerations. But, in this case, scientists knocked out the gene in 41 human embryos donated by couples who had undergone in-vitro fertilization (IVF). The researchers claim the switch allowed them to highlight key differences between the role of OCT4 in human and mouse models. The team are hoping their findings can help scientists better grasp why some women suffer more miscarriages than others. Additionally, the study could also increase the rate of successful IVF procedures.

This isn't the first time scientists have used human embryos. Earlier this year, a team of researchers from Oregon became the first to use CRISPR tech to cut out genes that cause inherited diseases in humans. Before that, scientists in China utilized the technique to repair a gene that can bring about a fatal blood disorder.

The new study is being hailed as a compelling first step. "We were surprised to see just how crucial this gene is for human embryo development, but we need to continue our work to confirm its role," Norah Fogarty of the Francis Crick Institute told CNN. "Other research methods, including studies in mice, suggested a later and more focused role for OCT4, so our results highlight the need for human embryo research."