Oxidative stress (OS), a state characterized by an imbalance between pro-oxidant molecules including reactive oxygen and nitrogen species, and antioxidant defenses, has been identified to play a key role in the pathogenesis of subfertility in both males and females. The adverse effects of OS on sperm quality and functions have been well documented. In females, on the other hand, the impact of OS on oocytes and reproductive functions remains unclear. This imbalance between pro-oxidants and antioxidants can lead to a number of reproductive diseases such as endometriosis, polycystic ovary syndrome (PCOS), and unexplained infertility. Pregnancy complications such as spontaneous abortion, recurrent pregnancy loss, and preeclampsia, can also develop in response to OS. Studies have shown that extremes of body weight and lifestyle factors such as cigarette smoking, alcohol use, and recreational drug use can promote excess free radical production, which could affect fertility. Exposures to environmental pollutants are of increasing concern, as they too have been found to trigger oxidative states, possibly contributing to female infertility. This article will review the currently available literature on the roles of reactive species and OS in both normal and abnormal reproductive physiological processes. Antioxidant supplementation may be effective in controlling the production of ROS and continues to be explored as a potential strategy to overcome reproductive disorders associated with infertility. However, investigations conducted to date have been through animal or in vitro studies, which have produced largely conflicting results. The impact of OS on assisted reproductive techniques (ART) will be addressed, in addition to the possible benefits of antioxidant supplementation of ART culture media to increase the likelihood for ART success. Future randomized controlled clinical trials on humans are necessary to elucidate the precise mechanisms through which OS affects female reproductive abilities, and will facilitate further explorations of the possible benefits of antioxidants to treat infertility.

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The effects of oxidative stress on female reproduction: a review

Origins of lifetime health around the time of conception: causes and consequences.

Approximately 10 to 15% of couples are impacted by infertility. Recently, the pivotal role that lifestyle factors play in the development of infertility has generated a considerable amount of interest. Lifestyle factors are the modifiable habits and ways of life that can greatly influence overall health and well-being, including fertility. Many lifestyle factors such as the age at which to start a family, nutrition, weight, exercise, psychological stress, environmental and occupational exposures, and others can have substantial effects on fertility; lifestyle factors such as cigarette smoking, illicit drug use, and alcohol and caffeine consumption can negatively influence fertility while others such as preventative care may be beneficial. The present literature review encompasses multiple lifestyle factors and places infertility in context for the couple by focusing on both males and females; it aims to identify the roles that lifestyle factors play in determining reproductive status. The growing interest and amount of research in this field have made it evident that lifestyle factors have a significant impact on fertility.

/pdf/lifestyle-factors-and-reproductive-health-taking-control-of-ob45s39pgz.pdf

Lifestyle factors and reproductive health: taking control of your fertility

Obesity and Female Infertility: Potential Mediators of Obesity's Impact

The negative impact of obesity on reproductive success is well documented but the stages at which development of the conceptus is compromised and the mechanisms responsible for the developmental failure still remain unclear. Recent findings suggest that mitochondria may be a contributing factor. However to date no studies have directly addressed the consequences of maternal obesity on mitochondria in early embryogenesis.

Using an established murine model of maternal diet induced obesity and a live cell dynamic fluorescence imaging techniques coupled with molecular biology we have investigated the underlying mechanisms of obesity-induced reduced fertility. Our study is the first to show that maternal obesity prior to conception is associated with altered mitochondria in mouse oocytes and zygotes. Specifically, maternal diet-induced obesity in mice led to an increase in mitochondrial potential, mitochondrial DNA content and biogenesis. Generation of reactive oxygen species (ROS) was raised while glutathione was depleted and the redox state became more oxidised, suggestive of oxidative stress. These altered mitochondrial properties were associated with significant developmental impairment as shown by the increased number of obese mothers who failed to support blastocyst formation compared to lean dams. We propose that compromised oocyte and early embryo mitochondrial metabolism, resulting from excessive nutrient exposure prior to and during conception, may underlie poor reproductive outcomes frequently reported in obese women.

/pdf/maternal-diet-induced-obesity-alters-mitochondrial-activity-4pc7wwtdu4.pdf

Maternal diet-induced obesity alters mitochondrial activity and redox status in mouse oocytes and zygotes.

Context: Obese women experience longer times to conception, even if they are young and cycling regularly, which is suggestive of alterations in ovarian function during the periconceptual period. Objective: This study sought to determine whether there are alterations in the preovulatory follicular environment that are likely to influence oocyte developmental competence. Design, Setting, and Participants: Women attending a private infertility clinic were categorized into body mass index (BMI) groups of moderate (n = 33; BMI 20–24.9 kg/m2), overweight (n = 31; BMI 25–29.9 kg/m2), and obese (n =32; BMI ≥30 kg/m2). Intervention: For each patient, follicular fluid was recovered from single follicles at oocyte retrieval, granulosa cells were pooled from multiple follicular aspirates and cumulus cells were pooled after separation from the oocytes. Main Outcome Measures: Follicle fluid was assayed for hormones and metabolites. Granulosa and cumulus cells were analyzed for mRNA expression of insulin signaling compo...

Obese Women Exhibit Differences in Ovarian Metabolites, Hormones, and Gene Expression Compared with Moderate-Weight Women

https://www.fertstert.org/article/S0015-0282(12)00268-3/pdf

Exposure to lipid-rich follicular fluid is associated with endoplasmic reticulum stress and impaired oocyte maturation in cumulus-oocyte complexes

Effects of obesity on assisted reproductive technology outcomes.

‘A record number of women are affected by what the WHO has termed ‘globesity’ at the same time infertility rates are escalating.’ Lifestyle factors play a crucial role in a woman’s ability to conceive and maintain a healthy pregnancy. Women of all ages vary in their fecundability and fertility, and a major contributing factor to achieving a healthy pregnancy is maternal preconception health. Infertility rates are on the rise and affect an estimated 15% of couples in industrially developed countries [1]. Infertility is diagnosed if a couple is unable to achieve a pregnancy after 12 months of unprotected intercourse and spans a broad spectrum of conditions, including diagnoses such as ovulatory disorders, tubal disease, endometriosis, chromosomal abnormalities, sperm factors and unexplained infertility. Mounting evidence has shown that maternal preconception weight can set the stage for conception and beyond. Many studies have reported a U-shaped effect of body mass, and women at either extreme experience endocrine and metabolic alterations that can affect their ability to ovulate and conceive. BMI is a measure of body weight and is calculated as weight (kg) divided by height 2 (m). Healthy- or normal weight individuals have a BMI in the range of 20–24.9 kg/m 2 , while 25.0–29.9 kg/m 2 is overweight and 30 kg/m 2 and over is classified as obese. A record number of women are affected by what the WHO has termed ‘globesity’ at the same time infertility rates are escalating. The consequences of these health conditions are farreaching and affect women of all ethnic groups, all ages and all educational and socioeconomic levels. The prevalence of processed or fried foods in the Western diet, coupled with an increase in sedentary behavior, has resulted in a staggering increase in the number of women who are overweight or obese. The obesity epidemic continues to compromise health, quality

https://journals.sagepub.com/doi/pdf/10.2217/17455057.3.5.511

Lindsay R. Chura

Papers

Obese Women Exhibit Differences in Ovarian Metabolites, Hormones, and Gene Expression Compared with Moderate-Weight Women

Exposure to lipid-rich follicular fluid is associated with endoplasmic reticulum stress and impaired oocyte maturation in cumulus-oocyte complexes

Effects of obesity on assisted reproductive technology outcomes.

Impact of lifestyle factors on ovarian function and reproductive health in women.