<prompt> True about hCG is :Alfa subunit identical to LH, FSH and TSHCauses involution of corpus luteumDoubles in 7-10 daysMaximum level seen at 50 days of gestation  <response>: hCG is a glycoprotein with high sialic acid content. It bears a close structural similarity to the other glycoprotein hormones FSH, LH, and TSH all of whose alpha subunits are identical. It rescues and maintains corpus luteumtill 6 weeks of pregnancy. doubling time is 1.4-2days. maximum levels reach between 60-70 days of pregnancy. Reference: Dutta Textbook of Obstetrics 7th edition page 58 