Human chorionic gonadotropin (hcg)

NEET PG Obstetrics & Gynaecology
#1

HUMAN CHORIONIC GONADOTROPIN (HCG)

  • Glycoprotein

  • Functions: Maintenance of corpus luteum function till 6 weeks of pregnancy. It has got immune suppressive activity.

  • Secreted by syncytiotrophoblast.

  • It can be detected earliest in maternal serum or urine by 8-9 days after fertilization.

  • Peak level is seen at 60-70 days (10th week) of pregnancy.

  • Doubling time is 48 hours.

  • It disappears from maternal urine 48 hours and maternal serum 2 weeks following delivery.

  • Cut off value for seeing gestation sac on Transvaginal USG is 1000- 1500 IU.
    On Transabdominal USG is 6000-6500 IU.
    -Fundal Height is felt at the level of Umbilicus at 24 weeks.

  • Fetal heart rate (FHR) is most conclusive clinical sign of pregnancy. Normal FHR is 110-160 bpm.

  • Cardiac activity can be detected by Transvaginal (TVS) as early as 6 weeks. Transabdominal- 7 weeks.

  • FHR can be heard by Doppler by 10th week.

  • Radiologically fetal skeletal shadow may be visible as early as 16th week.

  • Lightening is a symptom of 3rd trimester, there is sense of relief felt by mother.

  • Psuedocyesis: (False pregnancy, Phantom) is psychological disorder where the women has the false but firm belief that she is pregnant although no pregnancy exists. Physical examination, USG/Immunological tests required to negate the diagnosis.