Normally, the male chromosome is XY. In general, there are 23 pairs (or 46) of human chromosomes, 22 pairs of autosomes and one pair of sex chromosomes. Males have one Y chromosome and one X chromosome; while females have two X chromosomes. Thus, XY represents males and XX represents females. During the formation of sperm, meiosis of germ cells occurs, so the chromosomes within the sperm are split in two. At this point, half of the sperm carries the X sex chromosome and is called X sperm, while the other half carries the Y sex chromosome and is called Y sperm. If it is a Y sperm that combines with an egg cell, the sex of the baby born will be male and vice versa. If chromosomal abnormalities are present, patients are advised to seek prompt medical attention, and if they have reproductive needs, they can visit the Reproductive Medicine Clinic for counseling.