Human chorionic gonadotropin (hCG) is a hormone that is produced by the placenta during pregnancy. It can be detected in the blood and urine of pregnant women as early as 10 to 11 days after conception. The levels of hCG are highest towards the end of the first trimester, around 10 weeks of pregnancy, and then gradually decline over the rest of the pregnancy.
The hCG levels are measured in milli-international units per milliliter (mIU/mL). A level of less than 5 mIU/mL is considered negative for pregnancy, while anything above 25 mIU/mL is considered positive for pregnancy. The hCG levels can double every 72 hours, and 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.
The expected hCG ranges in pregnant women are based on the length of the pregnancy. For example, at 4 weeks, the average hCG levels in blood during pregnancy can range from 0 - 750 µ/L, and at 7 weeks, it can range from 3,000 - 160,000 µ/L.
A quantitative hCG blood test measures the specific level of hCG in the blood and can help determine the exact age of the fetus. It can also assist in the diagnosis of abnormal pregnancies, such as ectopic pregnancies, molar pregnancies, and possible miscarriages.
In summary, hCG levels play a crucial role in confirming pregnancy and providing details on how the pregnancy is progressing. The levels of hCG can vary for each woman, and it is not necessarily the level that matters, but rather the change in the level.
