For what situations are emergency contraceptives particularly useful?

Step-by-step solution

Progestogens alone or in combination with estrogen can also be used by females as injections or implants under the skin . Their mode of action is similar to that of pills and their effective periods are much longer. Administration of progestogens or progestogen-estrogen combinations or IUDs within 72 hours of coitus have been found to be very effective as emergency contraceptives as they could be used to avoid possible pregnancy due to rape or casual unprotected intercourse.