September 16, 2026
A Revolution in Women’s Midlife Health Care
At Midi Health, Ava Mainieri helps transform the way menopause is understood and treated.
An estimated 75 million US women suffer from symptoms related to menopause—from hot flashes and mood changes to sleep disturbances, joint pain, weight gain, and much more.
Despite menopause’s dramatic impact on well-being, the National Institutes of Health (NIH) allocates to it only a fraction of the already meager 9 percent of its research budget targeting women’s health. Moreover, many women have little access to qualified health care professionals who can help them manage the profound impacts of menopause: rural counties in the US average fewer than 2 obstetrician-gynecologists per 1,000 residents. Many of those doctors—perhaps as many as 80 percent—report feeling unprepared to manage menopause effectively.
Ava Mainieri, PhD ’20, wants to transform this aspect of women’s health care. As vice president of clinical operations at the fast-growing startup Midi Health, Mainieri is part of the effort to expand access to doctors who understand the challenges of midlife. In doing so, she hopes not only to bridge the gap in knowledge faced by women and their providers but also, ultimately, to help set a new standard of care for those in menopause.
Perimenopause and Its Discontents
The first thing to understand about menopause is that the symptoms most often associated with the term actually occur during perimenopause. "In the zeitgeist, we say menopause, but technically it’s perimenopause, menopause, and then postmenopause," Mainieri says.
Menopause, Mainieri explains, is the moment when menses have ceased for at least 12 months. In perimenopause, lower and lower levels of the hormones estrogen and progesterone are produced. Menstrual cycles become irregular, the drop in estrogen wreaks havoc with the body’s internal thermometer, and mood changes become more extreme as the brain tries to squeeze hormones from ovaries that have them in increasingly short supply. The process can begin as early as the late 30s, can last anywhere from one year to a decade, and affects the entire physiology.
"Why are the symptoms of perimenopause so widespread rather than being localized to your reproductive system? Because you have estrogen receptors in all parts of your body, from your skin to your bones to your ovaries," Mainieri explains. "And the impact on quality of life is huge. We joke about hot flashes, for instance, but it really feels like you’re burning alive."
A Model That Meets the Needs of Midlife
Mainieri says traditional health care is structured around incentives that often work against women in midlife. The fee-for-service model keeps visit times short. Perimenopause symptoms, which most clinicians are sparsely trained to treat, are often dismissed or patients are referred to a specialist, which presents additional challenges to access. Built around telehealth meetings accessible in all 50 states, Midi’s model seeks to eliminate barriers to access. "Patients can meet with their doctor online whether they’re in a car or at a cafe," Mainieri says.
"When you think of it through an evolutionary lens, menopause is kind of like pregnancy: a withdrawal of a system that was doing a lot of work behind the scenes." —Ava Mainieri
Virtual visits and prescriptions are covered by major insurance carriers like Blue Cross, Aetna, Cigna, and UnitedHealthcare (but not yet Medicare and Medicaid). "All you really have to do is book a visit, pay your copay, and then you can be with us as long as you want. We specialize in midlife care, but we see patients age 18 and older. We can take care of that whole breadth of adult life."
The organization’s more than 550 clinicians complete 80 hours of rigorous, menopause-specific training. For mammograms, ultrasounds, or other diagnostics, Midi boasts an extensive list of vetted referral partners. "We make sure we’re sending you to someone whom we like and trust, and you’re not going to be dismissed when you go there," Mainieri says.
Finally—and perhaps most of all—Midi emphasizes the relationship building that is foundational to the delivery of high-quality care. "You’re going to talk to a clinician who’s been specifically trained in perimenopause and menopause care. Most of all, you’re going to see the same clinician over and over again, so she understands who you are as a person and can help guide you to the best treatment or intervention for your specific symptoms. And then thinking 10 years down the line, she can help you age gracefully and healthfully."
At Midi, Mainieri focuses on results. Are patients getting better? Are clinicians delivering good care? And how do leaders know? "I lead a group that’s developed around 50 protocols because menopause as a field has been unstandardized, and our clinicians have been using evidence-based frameworks."
Once the protocols are built, Mainieri supervises the effort to track adherence to them. The organization’s goal is for clinicians to follow protocol at a rate of more than 90 percent, including complex clinical decisions.
"If you have a uterus, you have to be on estrogen and progesterone both to prevent endometrial or uterine cancer," she explains. "That is a safety concern. So, we want to make sure that every single one of our patients who need to be on a progesterone medication is actually taking it, rather than unopposed estrogen. It’s the protocol development, the patient outcomes, measuring quality, making sure that we’re delivering good, safe care, and then, again, swooping in and fixing when we’re not."
Dr. Kathleen Jordan, Midi’s chief medical officer, says Mainieri’s PhD work and ability to think critically help the leadership team translate the science into practical solutions. "Ava never stops learning and with that knowledge helps us iterate and deliver care that truly reflects best practices and always improving with new and emerging science and care tools," Jordan says. "She is multitalented, but her acumen is particularly outstanding when looking and developing new care approaches, informed by new and emerging science. She leads many of our discussions here, working collaboratively with our clinical leaders."
Midi’s chief clinical officer, Dr. Mindy Goldman, says Mainieri helps ensure every aspect of care is grounded in science, overseeing the development of clinical protocols, and monitoring outcomes to ensure high standards. "By partnering across our clinical, operations, and product teams, Ava helps translate research into practice, evaluate the quality and consistency of the care we deliver, and identify new opportunities to better support our patients," she says. "Her scientific curiosity, collaborative approach, and commitment to excellence have helped shape the high-quality care that defines Midi."
Leveraging AI for Women’s Health
Firms in the health care sector, as elsewhere, have great hopes about artificial intelligence’s (AI) ability to lower costs, while improving the productivity of providers and the quality of the care they deliver. Unlike generative AI platforms like ChatGPT, for instance, the clinically focused Open Evidence platform restricts its data retrieval to medical literature: major journals like the New England Journal of Medicine, JAMA and the JAMA Network of specialty journals, and the Wiley Online Library; clinical guidelines from organizations such as the National Comprehensive Cancer Network, and review bodies like Cochrane Systematic Reviews, as well as a raft of medical society partners. But Mainieri notes that, here too, gender matters.
Ava’s attention to the subtleties of evolutionary trade-offs will be useful in this important work.
—David Haig, George Putnam Professor of Organismic and Evolutionary Biology
"The biggest challenge is that most AI tools in health care are still built on data that reflects decades of underresearch in female physiology," she says. "Those gaps are encoded into the AI. The output is only as good as the clinical knowledge underneath it."
To address those gaps, Midi brought AI in-house, developing models trained on the most recent menopause research. "We’re really in an unusual position, because we have something like 200,000 plus patients in this specific demographic," says Mainieri, "which means that the sample we’re working with is far more representative than what most health AI is trained on. We have board-certified MDs who help craft protocols geared specifically to that population."
Moreover, AI supports Midi clinicians in real time during a patient visit. "If a patient asks an esoteric question, the clinician can say, 'Hold on one second. Let me look that up for you right now.' And it gives her an answer that comes from our own protocols. It provides decision support when the clinician actually needs it, not when the appointment is over."
Ancient Systems, Modern Medicine
Mainieri’s path to Midi followed from her PhD work at Harvard Griffin GSAS. As a student in organismic and evolutionary biology, her research examined how the same genes express themselves differently depending on parent of origin. She also investigated how deeply rooted, ancient hormone systems can be disrupted by environmental factors.
"For example, the estrogen signaling system is ancient," Mainieri explains. "It does things far beyond production. It’s involved in inflammation regulation, bone metabolism, neural function, and cardiovascular protection. When you think of it through an evolutionary lens, menopause is kind of like pregnancy: a withdrawal of a system that was doing a lot of work behind the scenes."
Mainieri’s PhD advisor, George Putnam Professor of Organismic and Evolutionary Biology David Haig, says her work on the ancient functions of oxytocin was particularly notable. "Oxytocin is popularly known as a 'love' or 'trust' hormone, but has ancient functions in uterine contraction during labor and milk let-down, and effects on appetite," he says. "Ava related the evolution of these disparate functions from ancient forms of parental care—including not eating your hard-won offspring!"
Mainieri’s framing of the menopausal process in terms of pregnancy is more than just semantics; it enables clinicians to think about what symptoms to look for and what downstream effects to anticipate with treatment. The estrogen example also highlights the importance of hormone therapy across multiple organ systems: bones, brain, and heart.
"The training I got at Harvard Griffin GSAS in this type of systems thinking is really what good menopause care requires," she says. "It’s not just one intervention, and then you’re going to be fine. It’s 'How do we work and tinker this together?' It’s why I like menopausal care so much."
Mainieri’s passion for women’s health is also personal. "I’ve had moments of watching the health care system fail to take me seriously," she says. "That’s why I jumped immediately from my PhD into working in women’s health. When I saw that Midi was treating menopausal women as a clinical area that deserved rigorous evidence-informed care, rather than a life event to be endured, it really clicked. And then the next question, of course, is 'How do we fix this? What do we do?'"
Growth Mentality
Midi’s model, and its focus on women’s health, has resonated both with patients and investors. Last winter, the company raised $100 million from firms like Foresite Capital, Advance Venture Partners, and Google Ventures. The funds brought Midi’s valuation to over $1 billion.
"Midi has grown many multiples year after year—and continues to grow," says Jordan. "We started with serving a few patients per day at our inception in 2021 and are now serving tens of thousands of women each week in 2026. We have delivered care to hundreds of thousands of women already and anticipate—and are building—a care system that is able to serve even more."
Mainieri says the reason for the company’s success is simple: pent-up demand. "The growth here, and in menopausal health care more broadly, reflects a genuine market failure that’s finally being addressed," she says. "Two million US women enter menopause each year. Many are told that the health care system doesn’t have much to offer them: 'There’s nothing we can do. It’s not that bad. Just turn up the air conditioner if you’re having a hot flash.' When you show up with actual clinical expertise, and a care model that acknowledges these symptoms are real and can be treated, you don’t have a marketing problem. The demand is already there."
In the years to come, Mainieri looks forward to helping Midi set the standard for menopause and, more broadly, women’s health. Harvard’s Haig says this goal is consistent with concerns and interests apparent in his former advisee’s research.
"Menopause is a distinctive aspect of human life history that poses an evolutionary puzzle: What explains the cessation of ovulation in healthy women with many years of life expectancy?" he observes. "Ava’s attention to the subtleties of evolutionary trade-offs will be useful in this important work."
When she describes what future success would look like, Mainieri’s words are those of a PhD researcher merged with a clinician, complemented by a commitment to access for patients up and down the economic ladder.
"Setting the standard means more published outcomes data, and a deeper evidence base built from our own patient population," she says. "It’s also a care model that women can actually access, including those for whom out-of-pocket telehealth is currently a barrier. That’s why we hope eventually to be able to accept Medicaid and Medicare."
At the core of Mainieri’s work—and Midi’s—is the ethic of listening to women whose suffering has been dismissed, discounted, and disregarded.
"The thing for us is that we believe you," she says. "We believe our patients. We want to send you to doctors who also believe their patients. When I’m telling you I’m feeling really hot, you believe that I’m experiencing a hot flash. The science that I care about is integrated with a population that I also care about, and that’s been underserved. That combination is why, hopefully, I’ll be in this field for many more years to come."
