Peak HCG levels are seen by what intrauterine age?

ANSWER: (A) 8-10 weeksREF: Dutta 6th ed p. 58.59f Current OB/GYN 10th ed chapter 8, William's 22th ed chapter 3Repeat from Primary DNB CET December 2011HUMAN CHORIONIC GONADOTROPHIN:* hCG is a glycoprotein composed of 2 subunits, alpha and beta. The alpha subunit is common to all glycoproteins, and the beta subunit confers unique specificity to the hormone. Typically, neither subunit is active by itself; only the intact molecule exerts hormonal effects.* Synthesized by syncytiotrophoblasts of the placenta* Half life is 32-37 hours, in contrast to that of most protein and steroid hormones, which have half-lives measured in minutes. which have half-lives measured in minutes.* In early pregnancy doubling time is 2 days* Can be detected as early as 9 days after the midcycle LH peak, which occurs 8 days after ovulation and only 1 day after implantation.* The hCG level above which one should identify an embryo by transvaginal ultrasonography (TVU) is now 1,000 to 2,000 mlU/mL, as determined by the second international standard.* Levels progressively rise and reach maximum by 8-10 weeks/60-80 days } 1st trimester* Falls until 18-20 weeks and remains low until term.* Disappears from circulation by 2 weeksWeeks of Gestation