This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis in Obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': "Increased acidosis and hypoxaemia is associated with: \nSelect and explain. \nA. Normal Doppler waveform, B. Increased fetal diastolic flow in the middle cerebral artery with absent diastolic flow in the aorta, C. Presence of the 'notch' in the uterine artery, D. Absent umbilical artery", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is b, i.e. Increased fetal diastolic flow in the middle cerebral artery with absent diastolic flow in the aortaRef. Williams Obs. 23/e, p 363, 364; Dutta Obs. 7/e, p 645Doppler Study of Middle Cerebral Vessels:Normally the middle cerebral vessels have high resistance flow and are characterized by little diastolic flow,In case of IUGR a brain-sparing effect is seen with a reduction in the resistance indices in the middle cerebral vessels (i.e. increased flow) due to the shunting of blood to the brain in IUGR. Whereas in other areas (as aorta in the options) show decreased flow."Increased fetal diastolic flow in middle cerebral artery with absent diastolic flow in aorta implies fetal acidemia." --Dutta Obs. 7/e, p 648As far as persistence of diastolic notch in uterine artery is concerned, it signifies pregnancies destined to develop preeclampsia.', 'role': 'assistant'}]