In vitro fertilization success rates are highest when patients undergo the procedure at younger ages, particularly under the age of 35. During this optimal biological window, women typically produce a higher quantity and superior quality of oocytes with lower rates of chromosomal abnormalities, which translates directly into higher fertilization, robust blastocyst development, and successful implantation rates. While reproductive technologies and hormonal stimulation protocols have advanced significantly to assist older patients, success rates decline progressively as maternal age advances, experiencing a sharper reduction after age 38 and more pronounced drops past age 40.