Research in mice has shown that an NMN supplement (Nicotinamide Mononucleotide) boosts Fertility even through aging. 
The NMN Supplement (Nicotinamide Mononucleotide) boosts Fertility by increasing NAD+ (nicotinamide adenine dinucleotide) levels in eggs. NMN supplementation facilitates egg maturity, improves egg quality, and promotes fertilization. Increasing NAD+ levels through NMN (Nicotinamide Mononucleotide) supplementation is a feasible, non-invasive way to enhance and protect female Fertility in the aging process. 
Aging and Infertility
The infertility rate worldwide is increasing because the quality of sperm and egg is decreasing. Women tend to wait until they are married for children past 35. However, once a woman turns 35, the chances of getting pregnant could become more complex, even if couples can get pregnant for over a year. 
Recent research in mammals suggests ways to minimize some of the effects of aging female reproductive systems and increase Fertility as we get to forty and beyond.
According to the Centers for Disease Control and Prevention (CDC), approximately 19% of women of reproductive age in the United States have difficulty having a child or supporting a pregnancy.
According to the World Health Organization (WHO), around 38 million married couples and 186 million worldwide cannot conceive. Infertility, which is not explained, is quite common.
With the grim figures, this is not a reason to be surprised that people are looking for ways to increase their Fertility. The rise in the infertility rate is not solely due to age. However, it is also due to lifestyle, diet, and poor sperm quality. In addition, there are problems or deficiencies with the fallopian tube, ovaries, and uterus. These issues could lead to reproductive problems. 
Alongside the discussed factors, additional factors impact Fertility.
- Cigarette Smoking
- History of pregnancy, e.g., miscarriage
- PCOS is a form of the polycystic ovarian syndrome. (PCOS)
- Hormonal imbalance
- The time it takes trying to think of
- Other medical conditions that may be underlying
- What is the relationship between NAD+ and Fertility? to Fertility?
- NAD+ directly improves egg quality and Fertility of females.
The metabolite NAD+ can be found in all body parts, which plays a vital function in the metabolism of cells and processes like autophagy, DNA repair cells' survival, cell survival, and immunity function. NAD+ levels decrease with age and are associated with a variety of diseases, including dementia, cardiovascular disease, and insulin resistance, which can cause the development of diabetes and obesity.
It has also been shown that NAD levels are believed to influence infertility, as evidenced by the reduced quantities of NAD in aging eggs. The intriguing aspect of the NMN was that the old mice that received it could increase the birth rate and reduce the time it takes to get pregnant.
Egg quality decreases quickly, making it harder to get pregnant. When NAD+ levels are maintained, it could increase the likelihood of becoming pregnant naturally or via IVF (In Vitro Fertilization). NAD+ is also connected to egg maturation by controlling cellular components. Avoiding eggs from losing too many of the basic elements is essential.
How do NMN Supplements Improve Fertility?
Based on animal research, taking an NMN supplement (Nicotinamide Mononucleotide) may stimulate a mammal's metabolic health, energy levels, and Fertility.
When there is an increase in NAD+ levels in eggs, the integrity of the DNA structure is maintained, and egg maturation occurs correctly. The integrity of DNA structure is necessary to cells, and in terms of fertility health, the unbalanced structure of DNA in eggs could cause infertility, miscarriages, or congenital disabilities.
NMN (Nicotinamide Mononucleotide) supplementation can also increase the sperm capacity attached to eggs and the chances of successful fertilization.
Another evidence-based study revealed that older mice receiving NMN supplements (Nicotinamide Mononucleotide) improved egg cell quality and increased ovulation rates. The blastocyst quality (the cell mass that will later become the embryo and eventually the fetus) has improved.
Further research has shown that increased NAD+ levels reverse the aging of the ovaries, resulting in healthy eggs due to the improvement of the function of the energy-producing machine, called mitochondria. So, it helps to support the cellular processes and rigor of eggs cell. 
Scientists looked through the microscope to determine what was happening to the eggs of old mice and found tremendous results. The eggs became healthier and improved the age-related defects.