A rare medical condition in which the uterus does not develop properly or is absent in a woman since birth. This congenital anomaly can occur in different degrees, from the complete absence of the uterus (uterine agenesis) to the incomplete development or severe malformation of the uterus. In formal academic and embryological contexts, it is commonly referred to as Müllerian aplasia, highlighting the developmental failure of the Müllerian ducts. The preferred term for this specific diagnostic entity in clinical and scientific literature is Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome.