Lab-Grown Sperm Breaks Infertility Barrier for Azoospermic Men

By VirentaNews Staff — May 26, 2026

Scientists and a biotech startup are advancing a technique to grow functional sperm in the lab from men with azoospermia—a condition affecting 1 in 100 males that prevents natural sperm production. This breakthrough could allow infertile men to father genetically related children, a possibility currently out of reach even with assisted reproductive technologies like IVF. While still experimental and not yet used in human pregnancies, the development marks a pivotal step in reproductive biology. If proven safe and effective, it may redefine fertility treatment for couples facing male-factor infertility, particularly those with non-obstructive azoospermia where no sperm are produced at all.

The Unmet Need in Male Infertility

Approximately 7% of men experience infertility, with azoospermia accounting for about 10% to 15% of these cases. Current treatments such as intracytoplasmic sperm injection (ICSI) rely on retrieving viable sperm from the testes, but this is impossible for men who produce none. Testicular sperm extraction (TESE) often fails in such patients, leaving donor sperm or adoption as the only options for parenthood. This gap has driven research into in vitro gametogenesis (IVG)—the process of creating eggs and sperm from stem cells. While IVG has succeeded in mice, human application has been hindered by the complexity of spermatogenesis and ethical concerns. Now, a startup, reportedly working with clinical collaborators, claims to have generated early-stage sperm cells from skin or blood cells of infertile men, reigniting hope for a biological solution.

From Skin Cells to Sperm: The Science Behind the Breakthrough

The technique begins by reprogramming adult cells—typically skin or blood—into induced pluripotent stem cells (iPSCs), which can differentiate into any cell type. These iPSCs are then coaxed through a series of biochemical signals to become primordial germ cells, the precursors to sperm. The cells are further matured using a testicular organoid system, a 3D lab-grown structure mimicking the testicular environment. According to Michael Le Page, New Scientist’s life sciences columnist, the startup has not yet produced fully mature, motile sperm capable of fertilization, but has achieved spermatid-like cells—the final stage before full sperm development. The process remains inefficient and is not yet ready for clinical trials, but it represents the most advanced progress to date in generating human sperm outside the body.

Why Gene Editing May Be Essential

One major obstacle is that many men with non-obstructive azoospermia have genetic mutations—such as deletions on the Y chromosome or mutations in genes like DAZ or CFTR—that impair sperm production. Simply growing sperm from their cells may reproduce the same defect. As Le Page notes, combining lab-grown sperm with gene editing tools like CRISPR could be necessary to correct these mutations before differentiation. This dual approach raises both promise and concern: while it could restore fertility, it also edges toward heritable genome modification, which is currently prohibited in many countries under international consensus. Research published in Nature has shown CRISPR can correct disease-causing mutations in human embryos, but applying it to gametes grown in vitro remains uncharted territory.

Implications for Patients and Reproductive Medicine

If perfected, this technology would transform reproductive options for infertile men, particularly those with genetic causes of azoospermia. It could reduce reliance on donor sperm, preserving genetic lineage and potentially improving psychological outcomes for families. Beyond male infertility, the method may benefit transgender individuals seeking biological children, as well as cancer survivors who lost fertility due to treatment. However, the therapy would likely be expensive and tightly regulated, at least initially. Moreover, children born from lab-grown sperm—especially if gene-edited—would require long-term monitoring for developmental and genetic health, echoing concerns raised during the early days of IVF.

Expert Perspectives

Reproductive biologists are cautiously optimistic. Dr. Aminata Touré, a stem cell researcher at the University of Cambridge, calls the work “a significant technical leap, but still far from clinical readiness.” Others warn against overpromising; Dr. Eliyahu Kresch of the Weizmann Institute cautions that “spermatogenesis involves over 2,000 genes and intricate cellular crosstalk—replicating this in a dish is immensely complex.” Ethicists emphasize the need for public dialogue, particularly if gene editing enters the equation. As noted by the Nuffield Council on Bioethics, interventions affecting future generations require broad societal consensus before deployment.

Looking ahead, the key milestones will be demonstrating fertilization capability in model systems, ensuring genomic stability of lab-grown sperm, and navigating regulatory frameworks. The startup behind the research has not disclosed timelines for clinical trials, but experts estimate at least five to ten years before potential availability—if safety and ethical standards are met. Meanwhile, researchers are refining organoid models and exploring non-editing workarounds, such as using healthy donor mitochondria or gene supplementation. As science inches closer to creating human gametes in the lab, society must confront not just whether we can, but whether we should.

Source: New Scientist