Partial moles are a type of abnormal pregnancy that occurs when an egg is fertilized by two sperm cells or when an egg with an abnormal number of chromosomes is fertilized. This results in the presence of both normal and abnormal placental tissue. Unlike complete moles, which contain only abnormal tissue, partial moles can sometimes develop a fetus, although it is usually not viable. Women with partial moles may experience symptoms such as vaginal bleeding, an enlarged uterus, or high levels of the hormone human chorionic gonadotropin (hCG). Diagnosis is typically made through ultrasound and blood tests. Treatment often involves monitoring and, if necessary, removing the abnormal tissue to prevent complications.