Just one month of every-other-day fasting was sufficient to improve oocyte quality [in mice]...Positive impact of intermittent fasting on aged oocytes was mediated by restoration of the nicotinamide adenine dinucleotide (NAD+)/Sirt1-mediated antioxidant defense system, which eliminated excessive accumulated ROS to suppress DNA damage and apoptosis.

NR treatment not only restored MII oocyte quality but also enhanced early embryonic development potential of postovulatory oocytes via alleviating mitochondrial dysfunction and maintaining normal spindle/chromosome structure. ...NR supplementation increases the oocyte quality and early embryonic development potential in post-ovulatory oocytes which could potentially increase the successful rate in assisted reproductive technology.

The rate of infertility continues to rise in the world for several reasons, including the age of conception and current lifestyle. We list in this paper potential non-invasive and invasive techniques to assess oocyte quality. We searched the database PubMed using the terms “oocytes AND quality AND evaluation”. In the first part, we study the morphological criteria, compartment by compartment, to then focus in a second part on more objective techniques such as genetics, molecular, apoptosis, or human follicular fluid that contain biologically active molecules. The main criteria used to assess oocyte quality are morphological; however, several other techniques have been studied in women to improve oocyte quality assessment, but most of them are invasive and not usable in routine.

The level of NAM in large follicles was significantly higher than that in small follicles. In mature FF, the NAM concentration was positively correlated with the rates of oocyte maturation and fertilization. Five mM NAM treatment during IVM increased maturation rate and fertilization rate in the oxidative stress model, and significantly reduced the increase of ROS levels induced by H2O2 in mice oocytes. Higher levels of NAM in FF are associated with larger follicle development. The supplement of 5 mM NAM during IVM may improve mice oocyte quality, reducing damage caused by oxidative stress...However, we found that an excessive NAM concentration inhibited the maturation and fertilization of oocytes.

It is well known that female reproduction ability decreases during the forth decade of life due to age-related changes in oocyte quality and quantity; although the number of women trying to conceive has today increased remarkably between the ages of 36 to 44. The causes of reproductive aging and physiological aspects of this phenomenon are still elusive. With increase in the women’s age, during Assisted Reproductive Technologies (ART) we have perceived a significant decline in the number and quality of retrieved oocytes, as well as in ovarian follicle reserves. This is because of increased aneuploidy due to factors such as spindle apparatus disruption; oxidative stress and mitochondrial damage. The aim of this review paper is to study data on the potential role of the aging process impacting oocyte quality and female reproductive ability. We present the current evidence that show the decreased oocyte quality with age, related to reductions in female reproductive outcome...

The NAD+ precursor nicotinamide riboside can protect against postovulatary aging in vitro…

Loss of follicles together with decreased oocyte quality and quantity contribute to age-associated ovarian senescence and infertility. Although underlying mechanisms for ovarian senescence are still unknown, mitochondrial dysfunctions have been reported. Here, we showed age-dependent decreases in ovarian Nicotinamide Adenine Dinucleotide (NAD+) levels in mice whereas supplementing aging mice with nicotinamide riboside (NR), an NAD+ precursor, increased ovarian NAD+ content. We found that increases in ovarian NAD+ levels in aging mice led to increased number of ovarian follicles and ovulatory potential as well as increased live birth rate...Our data suggested that supplementation with NAD+ precursors in vivo and in vitro could be potential therapeutic approaches for treating age-related ovarian infertility.

An adequate supply of healthy oocytes is essential for female fertility. Oocytes that sustain even very low levels of DNA damage are killed, presumably because the damage is irreparable. Surprisingly, however, we show that when apoptosis is inhibited, oocytes can repair severe DNA damage via homologous recombination repair. The repair is highly efficient; it protects fertility and ensures the health and genetic integrity of offspring. These data implicate DNA repair as an additional quality control mechanism available within the female germ line.

Declining oocyte quality is considered an irreversible feature of aging and is rate limiting for human fertility. Reversing an age-dependent decline in NAD(P)H restores oocyte quality, embryo development, and functional fertility in aged mice.

Oocyte quality is one of the most important factors involving in female reproduction. The number of compromised oocytes will increase with maternal age, while mitochondrial dysfunction has implicated in age-related poor oocyte...In this review, we summarize the potential mechanism of mitochondria in oocyte and embryo development and discuss the next step for mitochondrial transfer therapy.

In this review, using the latest literature, we discuss the pathophysiology in which oocytes are more exposed and vulnerable to oxidative stress as they age, and the mechanisms by which oocyte quality is degraded.

In this review, we provide a summary of the main putative causes for the age-related decrease in oocyte/embryo competence, along with the mechanisms underlying aging and the main clinical strategies proposed to prevent/limit the impact of advanced maternal age upon in vitro fertilization (IVF) success.