In a recent advance, researchers have succeeded in producing human eggs from skin cells, which were fertilized to form early-stage embryos under laboratory conditions. The study, published in Nature Communications, outlines the process and challenges, and represents a step toward in vitro gametogenesis (making eggs or sperm in the lab).1
The Oregon Health & Science University (OHSU) team employed a method known as somatic cell nuclear transfer (SCNT). First, they removed the nucleus from a donor egg cell. Then they inserted the nucleus of a skin (somatic) cell into that enucleated egg. 2
A fundamental issue is that skin cells are diploid (having two sets of chromosomes, 46 in humans), whereas eggs must carry a haploid set (23 chromosomes) to combine properly with sperm. To address this, the researchers induced a novel process they termed mitomeiosis, which discards half the chromosomes to simulate the natural reduction in gamete formation. 2
After creating these reprogrammed eggs, the team fertilized them with sperm in vitro. Among 82 eggs, approximately 9 % developed into blastocysts (an early stage of embryo formation). 1
Chromosome sequencing showed that the division and segregation of somatic chromosomes into the zygote and associated polar bodies was random and without recombination. Some resulting embryos had mismatches: some chromosome pairs were triploid or monosomic rather than a clean haploid complement. 2
Furthermore, implanted eggs occasionally arrested at metaphase — a cell division stage — unless artificially activated using a cyclin-dependent kinase inhibitor, which allowed the division process to proceed. 2
If refined and proven safe, this approach could help individuals or couples who cannot use their own eggs (due to age, disease, or treatments such as chemotherapy). It may also expand reproductive options for same-sex couples.
However, many researchers caution that this is a proof of concept stage. It may take at least a decade of additional work before clinical trials could be considered, assuming legal and regulatory frameworks evolve accordingly.
Low efficiency and high abnormality rates: Many fertilized eggs did not advance, and most displayed chromosomal anomalies.
Random segregation without crossover: Unlike natural meiosis, this artificial process lacked crossover and orderly alignment, limiting genetic stability.
No further development beyond blastocyst stage: The study did not progress embryos into later stages or attempt implantation.
Ethical, regulatory, and biological barriers: Before clinical use, questions around safety, consent, long-term viability, and risk (such as developmental errors) must be addressed.
The key takeaway is that scientists have shown it is possible to convert skin cell genetic material into egg-like cells that can fertilize and begin development — but the process is far from being safe or reliable. No pregnancies have been attempted with such embryos, and many technical hurdles remain.
References
“OHSU Researchers Develop Functional Eggs from Human Skin Cells.” OHSU News, September 30, 2025. https://news.ohsu.edu/2025/09/30/ohsu-researchers-develop-functional-eggs-from-human-skin-cells.
Marti Gutierrez, Nuria, Aleksei Mikhalchenko, Maria Shishimorova, Daniel Frana, Crystal Van Dyken, Ying Li, Hong Ma, Amy Koski, Dan Liang, Sang-Goo Lee, Daniel Eyberg, Zahra Safaei, Eunju Kang, Yeonmi Lee, Thomas O’Leary, David Lee, Sacha Krieg, Diana Wu, Elizabeth Rubin, Paula Amato, Shoukhrat Mitalipov, et al. “Induction of Experimental Cell Division to Generate Cells with Reduced Chromosome Ploidy.” Nature Communications 16, no. 8340 (2025). https://doi.org/10.1038/s41467-025-63454-7.
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