HCG doubling time is -

Ans. is 'b' i.e., 2 day Human chorion gonadotropin (HCG)o It is secreted by the syncytiotrophoblast of the placentao Its main function is to maintain the corpus luteum of pregnancyo Its doubling time is 1.5 to 2 dayso Maximum level is reached at 60-80dayso Most sensitive for detection of Beta HCG is radio immunoassay-detects after 8-9 days of fertilizationo It disappears within two weeks of delivery from circulation.