This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Congenital malformations, Subject name: Gynaecology & Obstetrics
[{'content': 'Diethvlstilbesterol causes the following defects except: \nSelect and explain. \nA. Renal anomalies, B. Perifimbrirl cysts, C. T shaped uterus, D. Vaginal adenosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In addition to its carcinogenic propeies, DES is a known teratogen, an agent capable of causing malformations in daughters and sons who were exposed in utero. DES-exposed daughters are at an increased risk of abnormalities of the reproductive tract, including vaginal epithelial changes such as vaginal adenosis (which means a type of cell normally found in the uterus, columnar cells, are also present in the vagina), an increased cervical transformation zone, and uterine abnormalities, such as T-shaped uterus.', 'role': 'assistant'}]