This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
Test not useful in case of tubal pregnancy: 
Select and explain. 
A. Pelvic examination, B. USG, C. hCG, D. Hysterosalpingography
D: Hysterosalpingography
Answer: D: Hysterosalpingography 
Explanation: HSG is usually done within 10 days of the period and after cessation of flow.This is inorder to reduce retrograde flow of the menstrual endometrium,which can result in infection and endometriosis.During menstruation the uterine veins are much dilated and this can cause increased vascular intravasation (refer pgno:125 sheila gynaec 2 nd edition)