Lactational amenorrhea prevents

Oral contraceptives prevent:

'Nirodh' is a popular brand of

In birth control methods,which one is an intra-uterine device?

Which of the following 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 if administered within $72$ hours?
$A.$ Administration of progestogens
$B.$ Progestogen-estrogen combinations
$C.$ $IUDs$ inserted within $72$ hours of coitus

Amniocentesis is one of the methods