This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'All of the following are components of placental barrier, EXCEPT: \nSelect and explain. \nA. Trophoblast, B. Fetal capillary endothelium, C. Mesoderm, D. Amnion', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The fetal and maternal blood is never in contact. They are separated by the placental barrier or placental membrane, which consists of: Syncytiotrophoblast Cytotrophoblast Basement membrane Mesoderm Endothelium of the fetal capillaries This thins out as term approaches due to attenuation of the syncytiotrophoblast. These thinned out areas, offer better exchange between the mother and fetus. Ref: Textbook of Obstetrics Sheila Balakrishnan, 1st Ed, page 75', 'role': 'assistant'}]