Question

Emergency contraceptives are effective if used within,

• A. 72 hours of coitus
• B. 72 hours of ovulation
• C. 72 hours of menstruation
• D. 72 hours of implantation

Answer 1

The correct option is A 72 hours of coitus

Emergency contraceptives are used after unprotected sexual intercourse within a particular time frame to avoid pregnancy.

Example: Hormone-based pill containing levonorgestrel.
The following actions of the pill have been proposed:
-Delay or prevent ovulation
-Leads to thickening of the cervical mucus to prevent sperm’s entry into the uterus
-Prevent implantation of the embryo.

The emergency contraceptives are effective if used within 72 hours of coitus, beyond which the success rate of the contraceptive reduces.

Emergency contraceptives do not directly affect menstruation and moreover, ovulation does not occur during the menstrual/bleeding phase. So, emergency contraceptives have no role to play during menses.

Ovulation is the release of the egg (secondary oocyte) from the ovary during the fertile phase. Not every ovulation result in pregnancy, unless there is unprotected coitus at that time. So, taking emergency contraceptives, merely within 72 hours of ovulation, without coitus, is of no use.

After implantation, the pregnancy is established. The pills do not induce an abortion of the implanted blastocyst. So, emergency contraceptives are ineffective after the implantation.