Weeks of pregnancy after last period Days after conception HCG level for single baby (mIU/ml or IU/L)
Week 3 0 to 5
Week 4 5 to 426
Week 5 18 to 7340
Week 6 2 1,080 to 56,500
Weeks 7 to 8 7,650 to 229,000
Weeks 9 to 12 25,700 to 288,000
Weeks 13 to 16 13,300 to 254,000
Weeks 17 to 24 4,060 to 165,400
Weeks 25 to birth of baby 3,640 to 117,000
4 to 6 weeks after birth Less than 5
Normal HCG blood levels vary widely between different women and in different pregnancies for the same woman. Be very careful when trying to 'interpret the numbers'. During the first 12 weeks of pregnancy, the level itself is NOT as important in how much it is rising every few days. Some normal pregnancies will have quite low HCG levels and still progress, ending in the birth of a healthy baby. The best way to confirm if a pregnancy is progressing is to repeat the blood test in 2 to 3 days time, and perhaps again 2 to 3 days after that. This is aimed at seeing if the HCG level is rising adequately.