Early in pregnancy, a hCG hormone is produced which tells the body conception has occurred. The presence of this hormone, hCG (or human chorionic gonadotropin), sets into place a chain of events, including the continued ovarian production of the hormone progesterone, which helps to sustain the uterine lining and prevents menstruation from starting. It is the hormone that home pregnancy tests look for as well as blood tests at the doctor.

In general the hCG levels will double every 72 hours. The level will reach its peak in the first 8 - 11 weeks of pregnancy and then will decline and level off for the remainder of the pregnancy.

hCG levels during pregnancy:
in weeks since last menstrual period / Amount of hCG in mIU/ml (hCG level for single baby)

• 3 weeks LMP / 5 - 50 mIU/ml (less than 5 means you are not pregnant)
• 4 weeks LMP / 5 - 426 mIU/ml
• 5 weeks LMP / 18 - 7,340 mIU/ml
• 6 weeks LMP / 1,080 - 56,500 mIU/ml
• 7 - 8 weeks LMP / 7,650 - 229,000 mIU/ml
• 9 - 12 weeks LMP / 25,700 - 288,000 mIU/ml
• 13 - 16 weeks LMP / 13,300 - 254,000 mIU/ml
• 17 - 24 weeks LMP / 4,060 - 165,400 mIU/ml
• 25 - 40 weeks LMP / 3,640 - 117,000 mIU/ml
• 4 - 6 weeks after birth / less than 5 mIU/ml

These numbers are just a GUIDELINE - Every woman’s level of hCG can rise differently. It is not necessarily the level that matters but rather the change in the level.