A woman’s fertility peaks between 20 and 30 years old and then gradually declines. This decline affects both the quantity and quality of eggs, becoming more pronounced after the age of 35-37. The main concern with aging eggs is the increased risk of chromosomal abnormalities (aneuploidy). As a woman gets older, a growing number of eggs develop genetic errors, which can lead to fertilization failure, implantation issues, or miscarriage in early pregnancy.  

When an embryo has an abnormal number of chromosomes, it may not develop properly. In some cases, such as trisomy 13, 18, or 21, the pregnancy may progress, but only trisomy 21 (Down syndrome) is compatible with life. Other chromosomal abnormalities often lead to early pregnancy loss.  

Beyond chromosomal issues, aging eggs also show:  

- Increased DNA fragmentation, which affects embryo development.  

- Mitochondrial dysfunction, meaning the egg’s energy supply is compromised.  

- Higher rates of genetic mutations, making successful fertilization and pregnancy less likely.  

How Is Ovarian Reserve Measured?  

A woman’s ovarian reserve refers to the number of remaining eggs at any given time. The most precise way to assess this would be through surgical sampling of ovarian tissue, but this is too invasive for routine use. Instead, doctors rely on hormonal blood tests and ultrasound evaluations.  

- Anti-Müllerian Hormone (AMH): A blood test measuring AMH levels provides an estimate of ovarian reserve.  

- Antral Follicle Count (AFC): An ultrasound scan counts the small follicles in the ovaries, which indicates the remaining egg supply.  

Learn. Improve. Maintain.  

Understanding how age impacts fertility helps women make informed reproductive choices. Learning about ovarian reserve, improving egg health through lifestyle and medical strategies, and maintaining regular check-ups with a fertility specialist can help optimize chances of conception.