Fertilization: The process of combining the male gamete, or sperm, with the female gamete, or ovum. The product of fertilization is a cell called a zygote. QUESTION The first sign of pregnancy is most often: See Answer From Healthy Resources Podcast Episode: What Is CMV?Can Your Fetus Be Tested for CMV?Who's on Your Child's CMV Care Team? Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19