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
All are associated with hydramnios except: 
Select and explain. 
A. Premature labour, B. Gestational diabetes, C. Renal agenesis, D. Increased amniotic fluid
C: Renal agenesis
Answer: C: Renal agenesis 
Explanation: None