Although DNA damage is rather prevalent in the human body, most cells are capable of detecting and correcting damage to their own genetic code. While immature sperm in the process of maturation may have some potential to repair their own DNA, mature sperm do not. Eggs can compensate for this in certain ways, and after fertilization, they have their own systems for repairing sperm DNA mistakes. However, if the damage is too severe—or if the egg is unable to repair it owing to age—the harm may persist until the embryo stage. The embryo may fail to grow or implant, resulting in infertility, miscarriage (which may occur again), or genetic defects or sickness in the baby.