New Research Reveals How Ovaries Age and What It Means for Your Fertility
When it comes to fertility, age matters. But until now, scientists haven't fully understood exactly how ovaries age at the cellular level. A groundbreaking study published in Science has created the most comprehensive map yet of ovarian aging in both humans and mice, revealing surprising insights that could change how we approach fertility preservation and treatment.
Understanding Ovarian Reserve
Your ovarian reserve—the number of eggs you're born with—doesn't just decline with age. This study used advanced 3D imaging to track exactly when and how follicles (the structures containing eggs) decrease over time. In mice, researchers found that secondary follicles began disappearing as early as 4 months of age, well before the total follicle count dropped significantly at 9 months.
In human ovaries, the researchers discovered something fascinating: rather than eggs being evenly distributed, they found "pockets" of eggs separated by follicle-free zones in women of advanced reproductive age (over 35). This uneven distribution may explain why fertility becomes less predictable as we age.
What this means for you: Current ovarian reserve testing (like AMH levels and antral follicle counts) provides snapshots of your fertility potential, but this research suggests the quality and distribution of follicles matters just as much as the quantity.
Your Nervous System Influences Egg Development
Perhaps the most surprising discovery involves sympathetic nerves—the same nerves involved in your "fight or flight" response. The study found that these nerves play an active role in follicle recruitment and maturation. When researchers removed sympathetic nerves in mice, the ovaries had more primordial follicles (the earliest stage) but fewer mature follicles ready for ovulation.
Even more interesting: sympathetic nerve density increased in aging ovaries of both mice and humans. This suggests your nervous system's influence on your ovaries changes over time, potentially contributing to age-related fertility decline.
Could this also be one of the ways acupuncture supports fertility?
I found this research especially revealing when I consider how acupuncture supports fertility. One primary mechanism for acupuncture's influence on fertility is its ability to calm the nervous system. Research in humans and animals shows that acupuncture affects nerve fibers in the muscles and tissues where needles are inserted. The needles downregulate an activated nervous system, relaxing tense muscles, increasing local blood flow, and releasing stress-reducing endorphins. When combined with a whole health approach to care, the impact of stress may be dampened.
What this means for you: This connection between your nervous system and ovarian function highlights why whole-person health matters for fertility. Chronic stress, which activates sympathetic nerves, may directly impact how your follicles develop. Acupuncture, mind-body practices, stress reduction, and nervous system regulation aren't just helpful for emotional wellbeing—they may support ovarian health at a biological level.
Egg Quality Declines Before Quantity
Using cutting-edge single-cell analysis, researchers examined over 90,000 cells from mouse and human ovaries. They discovered that oocytes (eggs) showed greater age-related changes than the surrounding support cells (granulosa cells). Importantly, human eggs showed the most significant changes in their most mature stages, which may explain why embryo quality declines sharply after age 35.
The study found that aging eggs showed:
Decreased expression of genes involved in chromosome organization (increasing aneuploidy risk)
Increased DNA damage response genes
Changes in genes controlling egg structure and sperm binding
In mice undergoing IVF, egg competence remained stable until 6 months of age, then declined significantly, even before the total egg count dropped substantially.
What this means for you: This research supports fertility preservation before age 35 when egg quality is typically optimal. It also explains why pregnancy rates decline with age even when ovarian reserve testing looks normal. The eggs themselves are changing at the molecular level.
The Whole-Body Approach to Ovarian Health
The study revealed that ovarian aging isn't isolated. It involves inflammation, changes in blood vessels, collagen accumulation (fibrosis), and nervous system changes. This comprehensive view emphasizes that your ovaries don't age in a vacuum; they're influenced by your overall health.
The research identified several modifiable factors:
Inflammation increased with age in the ovarian microenvironment
Blood vessel changes affected nutrient and hormone delivery
Collagen production by ovarian cells actually decreased with age (likely a protective response against fibrosis)
Nerve density increased, potentially affecting hormone signaling
What this means for you: Supporting whole-person health through nutrition, stress management, sleep, exercise, and reducing inflammation with acupuncture may help optimize your ovarian environment. While we can't stop aging, we can potentially influence how our ovaries age by addressing these systemic factors.
Mouse Models and Human Fertility Research
This study directly compared mice and humans, revealing both similarities and important differences. While mice are valuable research models, the findings show that:
Human eggs follow more species-specific maturation patterns than mouse eggs
Steroidogenesis (hormone production) differs between species
Fibrosis develops differently with age
These insights help fertility specialists better interpret animal research and understand which findings translate directly to human fertility treatment.
The Path Forward
While this research doesn’t resolve the question about stress causing infertility, this comprehensive atlas of ovarian aging provides a foundation for developing new approaches to preserve fertility and extend reproductive lifespan. It also provides the rationale for integrating time tested therapies like acupuncture. The researchers identified potential therapeutic targets, including pathways that could be addressed through lifestyle interventions, supplements, or medical treatments.
Understanding that ovarian aging involves your eggs, supporting cells, blood vessels, immune system, and nervous system reinforces why integrative, whole-person approaches to fertility matter. Your reproductive health reflects—and is influenced by—your overall health.
If you're concerned about your fertility or considering preservation options, this research underscores the importance of early planning and preconception health optimization. Working with providers who address both advanced reproductive technology and whole-person wellness may offer the most effective path to building your family.
Contact us if you would like to learn more about how acupuncture and the whole system of East Asian Medicine can reduce stress and ultimately, support your fertility. In Portland, Oregon, fertility acupuncturist Dr. Lee Hullender Rubin, DAoM, MS, LAc, FABORM, has been integrating acupuncture and EAM alongside conventional fertility therapies for two and a half decades.
Study Citation: Gaylord, E.A., et al. (2025). Comparative analysis of human and mouse ovaries across age. Science, 10.1126/science.adx0659.
Photo by Samuel Rodriguez on Unsplash