:
Weeks of pregnancy (mIU/ml or IU/L)
Week 3 HCG = 0 to 5
Week 4 HCG = 5 to 426
Week 5 HCG = 18 to 7340
Week 6 HCG = 1,080 to 56,500
Weeks 7 to 8 HCG = 7,650 to 229,000
Weeks 9 to 12 HCG = 25,700 to 288,000
Weeks 13 to 16 HCG = 13,300 to 254,000
Weeks 17 to 24 HCG = 4,060 to 165,400
Weeks 25 to birth HCG = 3,640 to 117,000
4 to 6 wks after birth HCG = Less than 5
Be aware that even when a pregnancy is miscarrying the levels can slightly increase for a while, but not at the rate expected if the pregnancy was progressing normally. For example a serum HCG level of 3,400 IU/L on Saturday, followed by a level of 3,600 IU/L on Monday may be of concern, as the level should be more like 5,000 to 7,000 IU/L. Also it is normal for the HCG level to start decreasing after 12 weeks of pregnancy.
The HCG hormone can stay in a woman's blood at low levels for up to 4 to 6 weeks after a miscarriage.