International Women’s Day: Safeguarding Women’s Health Across the Lifespan with the Power of Science

Introduction

In recognition of International Women’s Day, we spotlight women’s health—a continuously evolving global healthcare issue. The year 2025 marks the 30th anniversary of the United Nations Fourth World Conference on Women, where the landmark Beijing Declaration was adopted. This pivotal document systematically outlined an action framework for advocating women’s rights, with a particular emphasis on the importance of health equality. According to data from the World Health Organization, women constitute nearly half of the global population, and their lifespan healthcare needs require not only tackling specific diseases but also establishing a systematic health support system.

Challenges in Women’s Health

From puberty through menopause, women’s health faces distinct challenges across the lifespan ^[1]. Notably, endometriosis affects approximately 10% of reproductive-age women and adolescents, frequently causing chronic pain that persists for decades while severely diminishing quality of life. Pregnancy complications remain a leading cause of maternal mortality worldwide. After entering menopause, women experience accelerated bone loss compared to men and a substantially increased risk of cardiovascular disease. While cervical cancer prevention and treatment have seen remarkable progress, ovarian cancer continues to present a critical unmet need, with five-year survival rates stagnating at around 40% – underscoring the urgent demand for breakthroughs in early diagnostic technologies and novel therapies (Figure 1).

Figure 1. Unique Challenges in the Landscape of Women’s Health from Puberty to Menopause

To address these pressing challenges, the Urogenital and Endocrine Diseases team at WuXi AppTec Biology is empowering partners’ research through precision animal models. Our team has successfully developed 26 standardized animal models spanning three key areas: gynecological cancers, reproductive endocrine disorders, and perinatal complications. Notably, our Polycystic Ovary Syndrome (PCOS) model enables concurrent evaluation of insulin resistance and reproductive dysfunction. The endometriosis model faithfully replicates disease specific cyclical symptoms and is suitable for associated pain response evaluation. The ovariectomy-induced menopause model captures the interplay between bone metabolism shifts and endocrine system changes. These tailored models provide robust experimental systems to support cutting-edge drug development.

Model Showcase:

Model 1: Mouse Polycystic Ovary Syndrome

PCOS ranks among the most prevalent endocrine disorders in women, impacting an estimated 8–13% of individuals during their reproductive years. This condition serves as the leading cause of ovulatory dysfunction and a primary contributor to infertility cases [2]. Clinically, PCOS manifests through hormonal dysregulation, resulting in menstrual irregularities, hyperandrogenism, and polycystic ovarian morphology. Beyond reproductive impacts, the disorder predisposes individuals to systemic metabolic complications, including obesity and type 2 diabetes. To address these complexities, researchers at WuXi AppTec have leveraged letrozole—an aromatase inhibitor that blocks androgen-to-estrogen conversion, thereby disrupting the hypothalamic-pituitary-gonadal axis—in combination with a high-fat diet (HFD) to establish a robust rodent model of PCOS. This preclinical model demonstrates hallmark features including persistent estrous cycle arrest, hyperandrogenemia, polycystic ovarian morphology, mild adiposity, and insulin resistance (Figure 2).

Figure 2. Mouse PCOS Model Induced by Letrozole combined with HFD (Source: Internal data from WuXi Biology) A. Body weight changes; B. Insulin resistance index; C. Serum testosterone levels; D. Estrous cycle; E. Ovarian histopathology; F. Corpus luteum counting; G. Ovarian polycysts counting.

Model 2: Mouse Endometriosis

Endometriosis, a chronic and often underdiagnosed condition, impacts roughly 190 million women and adolescents globally. Characterized by the growth of endometrial-like tissue outside the uterus, the disorder frequently causes debilitating symptoms such as severe menstrual pain, chronic pelvic discomfort, and infertility [3]. As an estrogen-driven disease, endometriosis can develop as early as menarche and persist until menopause, creating lifelong health challenges. To address these complexities, WuXi AppTec has established a robust mouse model of endometriosis using surgical transplantation or perfusion techniques. In this model, ectopic lesions form on peritoneal surfaces, mesenteries, and other abdominal sites, eliciting pronounced pain sensitivity. These phenotypes are significantly alleviated by the GnRH analog cetrorelix acetate, indicating that the model is both responsive and physiologically relevant (Figure 3).

Figure 3. Mouse Model of Endometriosis Induced by Transplantation (Source: Internal data from WuXi Biology) A. Body weight changes; B. Paw mechanical pain threshold; C. Abdominal mechanical pain threshold; D. Transplanted tissue volume; E. Transplanted tissue weight; F. Histopathology of transplanted tissue.

Model 3: Rat Menopause

Women spend nearly one-third of their lives in menopause or post-menopause, a proportion expected to grow alongside increasing global life expectancy. With aging, declining ovarian follicle function drives a sharp reduction in estrogen production, culminating in fertility loss [4]. During the menopausal transition and beyond, diminished estrogen levels trigger a constellation of symptoms—collectively termed menopausal syndrome—that impair quality of life through physical and psychological discomfort. To study these effects, WuXi AppTec developed a rat model via bilateral ovariectomy (OVX), which reliably replicates clinical hallmarks of ovarian failure: menopausal obesity, uterine/vaginal atrophy, disrupted estrous cycles, reduced bone mineral density (BMD), and associated pathological changes. We verified that estrogen supplementation can reverse these symptoms in this model, demonstrating its translational relevance (Figure 4).

Figure 4. Ovariectomized (OVX) rat model (Source: Internal data from WuXi Biology) A. Body weight changes; B. Uterine weight; C. Vaginal weight; D. Estrous cycle; E. Bone mineral density (BMD); F. Histopathology of uterine, vaginal, and bones.

Conclusion

Throughout a woman’s life, from puberty to menopause, they face unique health challenges that significantly impact their quality of life. Advanced animal models, which accurately replicate the defining pathological features of female-specific conditions, provide a critical foundation for understanding disease mechanisms and validating therapeutic strategies. Over the past twenty years, global women’s health has seen significant improvements, largely due to targeted health research. WuXi Biology is committed to developing clinically relevant animal models to expedite the creation of novel treatments for conditions disproportionately affecting women. Our goal is to bridge healthcare gaps by translating preclinical insights into real-world impact, ultimately enhancing health outcomes for all women. This involves reducing menstrual pain, offering new pathways to overcome infertility, and tailoring hormone therapies to menopausal individuals.

References：

1. Carneiro MM. Women’s health in 2024: change now for tomorrow will be too late. Women & Health. 2024. 64(1):1-4. doi: 10.1080/03630242.2024.2292320.
2. Hoeger KM, Dokras A, Piltonen T. Update on PCOS: Consequences, Challenges, and Guiding Treatment. The Journal of Clinical Endocrinology and Metabolism. 2021. 106(3):e1071-e1083. doi: 10.1210/clinem/dgaa839.
3. Saunders PTK, Horne AW. Endometriosis: Etiology, pathobiology, and therapeutic prospects. Cell. 2021. 184(11):2807-2824. doi: 10.1016/j.cell.2021.04.041.
4. Gatenby C. Simpson P. Menopause: Physiology, definitions, and symptom. Best Practice & Research. Clinical Endocrinology & Metabolism. 2024. 38(1):101855. doi: 10.1016/j.beem.2023.101855.