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
In which part of fallopian tube ectopic pregnancy will have longest survival: 
Select and explain. 
A. Isthmus, B. Ampulla, C. Cornua, D. Interstitium
D: Interstitium
Answer: D: Interstitium 
Explanation: M.C site of ectopic pregnancy – Fallopian tubes.
In Fallopian Tubes – M/C sites in descending order are:

Ampulla > mus > infundibulum > interstitium

Rarest overall site of ectopic pregnancy is cervix or cesarean section scan
Average period of survival of ectopic pregnancy is 8 weeks.
Ectopic pregnancy survives for longest time in its annual pregnancy.