This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hydramnios and Oligo Hydramnios, Subject name: Gynaecology & Obstetrics
Oligohydramnios is seen in - 
Select and explain. 
A. Renal agenesis, B. Oesophageal atresia, C. Exomphalos, D. Neural tube defect
A: Renal agenesis
Answer: A: Renal agenesis 
Explanation: Ans. is 'a' i.e. Renal agenesis Renal agenesis prevents urine formation which leads to oligohydramnios.Oligohydramnios is condition where amniotic fluid is deficient in amount to the extent of 100ml or entirely absentAetiologyRenal agenesis*Amnion nodosum*IUGR*Post maturity*Obst. of urinary tract (post urethral Valve*)