The answer is Human chorionic gonadotropin. Estrogen, progesterone, testosterone, and follicle-stimulating hormone are present in non-pregnant women. However, chorionic gonadotropin is synthesised by the placenta during the pregnancy. After the fertilised egg attaches to the uterine wall, cells in the placenta, that serve for nourishing the egg, start to produce chorionic gonadotropin. Thus, its presence in the urine, indicates pregnancy.
