Egg Quality and Fertility

Egg quality is widely recognized as one of the most important factors affecting female fertility. However, the role of oxidative stress in compromising egg quality is often overlooked.

Background

All of the egg cells a woman will have throughout her lifetime are formed during fetal development. This means that the egg cells of a 31-year-old woman have existed for more than 31 years, making them uniquely vulnerable to cumulative damage over time. Like any other cell in the body, egg cells can be damaged by oxidative stress, which may negatively affect their quality and function.

Introduction

Oxidative stress occurs when there is an imbalance between reactive oxygen species (ROS)—unstable molecules that can damage cells—and the body’s protective antioxidants. In other words, oxidative stress develops when free radical production exceeds the body’s antioxidant defenses. Although some ROS are naturally produced during normal cellular metabolism, excessive levels are often linked to lifestyle and environmental factors. For example, diets high in processed foods, refined sugars, and unhealthy fats can increase free radical production, as can smoking and alcohol consumption. Environmental exposures such as air pollution, heavy metals, pesticides, and toxic chemicals may also contribute to oxidative stress by further disrupting the balance between antioxidants and damaging reactive molecules.

A review published in Reproduction and Fertility examined the role of lifestyle factors in fertility and reported that improving modifiable lifestyle factors may help restore normal oocyte maturation in women and improve semen quality in men.

“Nutrition and exercise may impact fertility both in men and women, good nourishment and a balanced diet should be encouraged. Infertile women should consume foods low in saturated fat, red meat, and high in vegetables, legumes, and antioxidants.”

Female Fertility and ROS

Oocytes, the foundation of female fertility, are particularly vulnerable to ROS due to their large size, huge number of mitochondria, high metabolic activity, prolonged maturation process, and limited ability to repair oxidative injury. In the absence of adequate antioxidant defenses, oxidative stress is formed damaging the quality of the egg cells and impairing fertility.

A 2025 review published in Reproductive Toxicology emphasized the importance of maintaining a balance between ROS and antioxidant defenses for preserving oocyte viability and function. The authors concluded that “oxidative stress represents a significant challenge in the realm of reproductive health, particularly concerning oocyte quality and fertility.”

A 2023 review published in Antioxidants examined the relationship between oxidative stress and female infertility and concluded that oxidative stress is associated with several reproductive and pregnancy-related complications, including endothelial dysfunction, recurrent pregnancy loss, intrauterine growth restriction (IUGR), hypertension, premature birth, ectopic pregnancy, and gestational diabetes.

Additional research published in 2025 further linked oxidative stress to reproductive disorders such as Polycystic Ovary Syndrome (PCOS), Endometriosis (EMS), Premature Ovarian Insufficiency (POI), and Recurrent Pregnancy Failure (RPF). The study also reported that elevated oxidative stress levels during Assisted Reproductive Technologies (ART) may compromise fertility outcomes, emphasizing the importance of strategies aimed at reducing oxidative damage.

“Oxidative stress represents a significant challenge in the realm of reproductive health, particularly concerning oocyte quality and fertility”

Male Fertility and ROS

Oxidative stress is considered one of the major contributors to male infertility. A paper published in the World Journal of Men’s Health titled “Effect of Oxidative Stress on Male Reproduction” reported that approximately 30% to 40% of infertile men in the United States have elevated levels of ROS in their seminal plasma. Another review published in 2019 in Cellular and Molecular Life Sciences stated that oxidative stress–induced sperm damage may contribute to infertility in 30% to 80% of infertile men.

One of the primary consequences of oxidative stress is sperm DNA fragmentation. Although a small degree of sperm DNA damage is considered normal, high levels of DNA fragmentation have been associated with reduced natural conception rates, lower fertilization rates, impaired embryo development, and an increased risk of early pregnancy loss.

A recent paper published in 2026 in Antioxidants analyzed the biological links between oxidative stress and sperm DNA fragmentation. In addition to highlighting the role of sperm DNA fragmentation in recurrent pregnancy loss (RPL), unexplained infertility, and repeated ART failure, the paper emphasized the importance of addressing modifiable contributors such as lifestyle factors, infection, inflammation, and clinical varicocele.

How to Reduce Oxidative Stress

Reducing oxidative stress involves restoring the balance between reactive oxygen species (ROS) and the body’s antioxidant defenses. One of the most effective ways to accomplish this is through lifestyle modifications, including a nutrient-rich diet, regular physical activity, avoidance of smoking, moderation of alcohol intake, and reduction of environmental toxin exposure. In addition to these measures, antioxidant supplementation has also been investigated as a potential strategy to support reproductive health.

Several studies have examined the role of antioxidant supplements in reducing oxidative stress and improving fertility outcomes. One retrospective study reported that reduced antioxidant status was associated with an increased risk of spontaneous abortion. Another study found that plasma levels of vitamins C and E were significantly lower in women with recurrent spontaneous abortion, suggesting that inadequate antioxidant defenses may contribute to pregnancy complications. Other well-researched antioxidants include: CoQ10, melatonin, NAC, alpha-lipoic acid, selenium, and zinc.

Acupuncture and ROS

Traditional Chinese Medicine (TCM) has been used in the treatment of infertility for more than 2,000 years. Chinese herbal medicine, acupuncture, and lifestyle practices—including Qi-moving exercises such as Qi Gong and Tai Chi, along with diets low in inflammatory foods—have historically been central components of TCM fertility treatment.

According to several studies, TCM therapies may help scavenge ROS, improve the antioxidant capacity of seminal plasma, reduce sperm DNA fragmentation, and protect the male reproductive system from oxidative damage.

A paper published in 2025 examined specific herbal formulations designed to reduce ROS with the goal of improving male fertility. The study concluded that TCM compounds may offer promising clinical applications for enhancing male reproductive function due to their multi-target and holistic regulatory effects.

Diminished Ovarian Reserve (DOR), a common cause of infertility, has been strongly associated with oxidative stress and excessive ROS. As described in a 2025 paper published in the Journal of Ovarian Research, elevated ROS levels can disrupt the balance between oxidative and antioxidant systems within the ovary contributing to several ovarian pathologies. The paper indicates that in recent years the advantages of TCM in treating DOR have become increasingly apparent. By recognizing the influence of menstrual cycle patterns and the physiological rhythms of Yin, Yang, Qi, and Blood, TCM allows for tailored treatment courses based on the physiological characteristics of patients during different phases of their menstrual cycles.

Conclusion

As demonstrated by numerous studies, oxidative stress is a major—yet often overlooked—factor in both female and male infertility. When the natural balance between reactive oxygen species (ROS) and antioxidants is disrupted, the first line of intervention should include lifestyle modifications aimed at reducing oxidative stress and improving overall health. Antioxidant supplementation may also provide additional support and should be considered as part of a comprehensive fertility approach.

Traditional Chinese Medicine (TCM) has a long history in the treatment of infertility and emphasizes the restoration of balance within the body. Although TCM approaches health from a different theoretical framework than conventional biomedicine, both perspectives recognize the importance of maintaining physiological balance for optimal reproductive function. From this perspective, reducing oxidative stress may be viewed as part of restoring the body’s internal equilibrium.