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
On Doppler studies which is an ominous sign for IUGR fetus : 
Select and explain. 
A. Increase S/D ratio, B. Reverse diastolic flow, C. Diastolic notch, D. All of the above
B: Reverse diastolic flow
Answer: B: Reverse diastolic flow 
Explanation: Absence of end-diastolic frequencies or reverse diastolic flow patterns in the umbilical aery usually indicates poor perinatal outcome. Reference: Dutta's Textbook of Obstetrics 7th edition page no 227