In which part of fallopian tube ectopic pregnancy will have longest survival:
Isthmus
Ampulla
Cornua
Interstitium
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.