A reproductive milestone may be underway. Many people who opt for assisted reproductive technology (ART) like in-vitro fertilization (IVF) often come away with unsuccessful results, with little explanation as to why it happens. With the treatments themselves being out of reach for many due to the costs involved, improving the chances of success could have significant implications. A new study that may have finally found an explanation for why IVF embryos fail, could pave the way for achieving just that.

Published in Cell earlier this week, researchers from the Columbia University Vagelos College of Physicians and Surgeons discovered how, contrary to previous expectations, chromosomal abnormalities that prevent the development of the embryo occur in the early, rather than the late stages of cell division.

Essentially, a fertilized egg begins to undergo cell-division within nearly 24 hours. This is when a cell splits into two new ones, called “daughter cells.” But before this happens, the fertilized egg creates two sets of the complete human genome — that’s two sets of 46 chromosomes each. This ensures that each daughter cell receives one complete set of 46 chromosomes.

Here is the crux of the problem with IVF: there’s an organelle called the microtubule spindle, which is responsible for actually splitting the cell into two. Before this study, researchers assumed that the incorrect distribution of chromosomes in each cell was due to the microtubule spindle malfunctioning in some way. But the new study shows that the problem arises much earlier — where the duplication itself is faulty, causing the spindle to malfunction as a consequence.

“This has largely been overlooked in previous studies — because why would the embryo allow the integrity of the genome to be compromised when this is such a critical requirement for normal development?” Dieter Egli, the study’s lead author, and Assistant Professor of Developmental Cell Biology (in Pediatrics), said.

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There’s still a missing piece to this puzzle: we don’t know why the duplication process goes wrong, but it might have to do with a deep-seated problem within the DNA itself. Researchers say that the next step would be to study this, alongside possible disease-causing impacts of DNA breakage due to incorrect duplication in IVF.

Meanwhile, the information we do have still advances progress in terms of understanding more about the implications of the technology itself, which could benefit those seeking it. “Many women undergoing fertility treatment require multiple IVF cycles in order to get pregnant, and some never get pregnant at all. Not only is this enormously expensive, it’s emotionally taxing,” said Jenna Turocy, a fertility specialist from the Columbia University Fertility Center and co-author of the study.

“I would be lying if I said the failures didn’t affect me — emotionally. It broke me every time the pregnancy test was negative,” Seema Tiwari, who tried IVF treatment repeatedly, told The Swaddle.

Knowing more about why reproductive technologies like IVF fail could help displace the blame from women’s bodies: previous research has shown that many opt out of ART because of the shame they experience when treatments fail, incorrectly attributing it to themselves.

This makes research on IVF to advance knowledge and improve its outcomes a reproductive rights issue. “Issues surrounding assisted reproduction implicate core human rights — including the rights to health, sexual and reproductive health, decision making about reproductive life (such as if and when to have children), benefit from scientific progress, equality and non-discrimination, and informed consent,” the Center For Reproductive Rights notes.