Which of the following is true regarding RU 486?
A. Prevents fertilization
B. Has affinity for estrogen receptors
C. Single dose of 10mg prevents pregnancy in 90% cases
D. Causes delayed menstruation
Correct answer : D. Causes delayed menstruation
RU 486 (mifepristone) does not prevent fertilization.
It has affinity for progesterone receptors.
It blocks the action of progesterone on the endometrium.
It prevents implantation by causing sloughing and shedding of decidua.
Single dose of 10mg prevents pregnancy in 99.1% cases.
Ref: Shaw’s Textbook of Gynaecology, 15th edition, p237.