Ovaries are one of the body's earliest-aging organs, and their decline shapes women's health for decades to come. While most people think of ovaries simply as reproductive organs, Northwestern University scientists are revealing that they're dynamic tissues that produce hormones, communicate with the rest of the body, and influence everything from bone health to heart disease risk long after a woman stops having periods.

The discovery is reshaping how reproductive medicine approaches women's health. For decades, fertility specialists, menopause experts, and aging researchers examined different aspects of the ovary in isolation, leaving significant gaps in understanding how ovarian aging affects overall health. Now, a unique collaboration among Northwestern physician-scientists is bringing these perspectives together to study the ovary more holistically and identify ways to slow its aging.

What Exactly Happens When Ovaries Age?

Ovarian aging is defined by the loss of egg quantity and quality that occurs throughout a woman's lifetime. Reproductive function begins to decline in women in their mid-30s and ceases completely at menopause. But the aging process doesn't stop there. In a serendipitous discovery, reproductive aging scientist Francesca Duncan's lab found that as ovaries age, they accumulate scar-like fibrotic tissue and inflammation that can impair ovarian function.

The finding completely shifted the field's focus. Researchers are increasingly recognizing that aging affects not only the eggs housed within the ovary but also the ovarian environment that supports them. In February 2026, a paper published in Science from scientists in China validated and extended Duncan's earlier findings about ovarian fibrosis from mice to humans and into clinical practice, marking a major advance for the field.

Duncan's latest work has pushed that idea even further. In a study published in June 2026, her lab found the post-reproductive ovary in older mice appears to transform into something resembling an immune organ, producing inflammatory signals long after reproduction has ceased. "I'm obsessed with this concept that the post-reproductive ovary is not defunct," Duncan stated. "It is definitely doing something, but what, we're still not sure of. I think that's where we'll see huge developments in the next 10 years."

"One of the big problems that has hindered women's health is this separation of reproduction and ovarian function, and I think we have to shift that discussion so that it's across the lifespan," said Francesca Duncan, reproductive aging scientist at Northwestern.

Francesca Duncan, Associate Professor of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine

How Are Scientists Measuring Ovarian Aging?

The challenge to measure ovarian aging has brought together researchers pursuing innovative approaches. Scientists like Duncan and Dr. Elnur Babayev are collaborating to noninvasively examine in humans how the mechanics of the ovary change with age. They're adapting technology commonly used to evaluate liver fibrosis to measure ovarian stiffness using ultrasound, and combining advanced imaging, molecular profiling, and single-cell analyses to identify measurable signs of ovarian aging in humans.

Duncan's team is also pursuing a blood test that could reveal fibrosis, tissue health, and ovarian-aging status. These developments represent an emerging effort to move ovarian aging from an abstract concept to a quantifiable biological process that doctors can actually measure and track.

Why Should Women Care About Ovarian Aging?

The implications extend far beyond fertility. In a June 2025 Nature Medicine commentary, Northwestern scientists argued that ovarian aging is a major, yet under-recognized, contributor to sex-based disparities in aging-related diseases. The research shows that ovarian aging drives higher rates of several serious health conditions:

• Neurological Disease: Higher rates of Alzheimer's disease and dementia among women after midlife
• Cardiovascular Health: Increased cardiovascular disease risk linked to ovarian aging
• Metabolic Dysfunction: Greater risk of metabolic disorders and obesity-related conditions
• Bone Health: Increased osteoporosis and impaired bone density
• Tissue Repair: Reduced ability to repair tissues and recover from injury
• Mental Health: Higher rates of depression in women after midlife

Measuring the biological age of women's ovaries could be the key to unlocking longer health spans, the length of time a person remains healthy and free from serious illness or chronic diseases. Since the ovary ages earlier than other organs, it may provide a glimpse into a woman's future health, predicting when she'll go through menopause, optimizing when hormone treatments can begin, and determining her risk of disease.

How Can This Research Change Women's Health Care?

The scientists argued that to truly transform reproductive medicine, public health, and research into women's health, ovarian aging should be recognized as a formal diagnosis, akin to how the field of obstetrics adopted the concept of "advanced maternal age." This shift would help doctors and patients understand that ovarian aging is not simply a fertility issue but a fundamental aspect of women's aging and health.

Dr. Kara Goldman, an associate professor of obstetrics and gynecology at Northwestern, came into women's health by way of cancer. Having watched young cancer patients undergo treatment, she realized that while the standard of care to preserve fertility is to freeze eggs or embryos, medicine does nothing to protect women's ovaries during chemotherapy. "The standard of care to preserve fertility is to freeze eggs or embryos, but we're doing nothing to protect women's ovaries," Goldman explained. That observation led her to a broader insight: infertility is only the most visible consequence of chemotherapy-induced ovarian aging.

"We're collaborating to not just study things in mice or in the lab dish, but actually bring it to our patients," said Dr. Elnur Babayev, who is working with Duncan to develop noninvasive ways to measure ovarian aging in humans.

Dr. Elnur Babayev, Assistant Professor of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine

The emerging research represents a fundamental shift in how medicine understands women's health. By recognizing the ovary not simply as a reproductive organ but as one of the body's earliest-aging tissues, scientists are opening new possibilities for understanding disease risk, extending healthy lifespan, and developing treatments that could slow ovarian aging itself. The blood tests and imaging techniques currently in development could soon give doctors concrete tools to measure this process and intervene before age-related diseases take hold.