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
Dose of Anti-D given to an Rh-negative ectopic pregnancy patient in first trimester is 
Select and explain. 
A. 10mcg, B. 25mcg, C. 40mcg, D. 50mcg
D: 50mcg
Answer: D: 50mcg 
Explanation: Regardless of location, D-negative women with an ectopic pregnancy who are not sensitized to D-antigen are given IgG anti-D immunoglobulin (American College of Obstetricians and Gynecologists, 2017). In first-trimester pregnancies, a 50-mg or 300-mg dose is appropriate, whereas a standard 300-mg dose is used for later gestations Reference: William's Obstetrics; 25th edition; Chapter 19; Ectopic pregnancy