During the pregnancy, a lab value that is checked regularly is "the beta number". This refers to the human chorionic gonadotropin or hcg, a hormone released during pregnancy and one of the major hormones made from cells in the placenta. Levels of hcg are detectable in maternal blood beginning with approximately 11 days after conception and in maternal urine approximately 12-14 days after conception.
Elevated hcg levels:
As the pregnancy progresses, the hcg levels increase approximately after every 96 hours.
In most cases, an hcg level above 25 mIU/ml is considered positive for pregnancy while below 5 mIU/ml is negative.
Guidelines for hcg levels (ask your local lab or clinical expert for the expected values before making any decisions based on hcg levels):
It starts at approximately 3 weeks after the LMP and the levels are between 5-50 mIU/ml
4 weeks after the LMP they usually are between 5-426 mIU/ml
During the 5th week, the range lies between 18-7340 mIU/ml
At 6 weeks, the range is 1080-56,500 mIU/ml.
At 7-8 weeks, the range is 7,650 - 229,000 mIU/ml
At 9-12 weeks, the range is 25,700 to 288,000 mIU/ml
During 13-16 weeks, the range should lie between 13,300 -254,000 mIU/ml
Between 17 - 24 weeks the range should be 4,060 - 165,400 mIU/ml
From 25- 40 weeks hcg should be 3,640 - 117,000 mIU/ml.