HCG or Human Chorionic Gonadotropin is a hormone that is secreted when you are pregnant. Basic home pregnancy tests and laboratories try to find a trace of this hormone and its presence in the body is basically a confirmation of pregnancy. HCG is a glycoprotein hormone that is released into the body by the placenta after the embryo is implanted. There are many sensitive pregnancy tests available in the market that can detect the HCG levels as early as 8 days after the fertilization.
HCG levels in blood and urine helps anxious mothers to detect positive pregnancy even before they miss their periods. Normal HCG levels in blood or urine should be less than 5 mIU/ml (5 IU/L) when you are not pregnant. HCG levels that are above 25 mIU/ml (25 IU/L) means that you are pregnant. If you are pregnant with twins or multiple fetuses, your HCG levels will also be double the standard pregnancy norm.
During the early weeks of pregnancy HCG levels will increase in every 48 to 72 hour period. But as you progress into pregnancy, the rate of increase for HCG levels will stabilize. In the initial weeks, the levels will be anywhere between 5 – 50 mIU/ml which will rise up to 50 – 426 mIU/ml during the fourth week of pregnancy. The levels increasing as the weeks progress. When the HCG levels are around 2000 mIU/ml the ultrasound would be able to detect the fetus. Around the seventh or eighth week, the HCG levels would be around 7650 mIU/ml – 229,000 mIU/ml. During the last few weeks of pregnancy, the HCG levels will decrease significantly due to impending childbirth.
Levels of HCG are also taken into consideration to detect ecoptic pregnancy in the early stage. Lower levels of HCG can also mean an impending miscarriage while unusually high levels of HCG can mean multiple pregnancy.
There are certain conditions when your HCG levels would rise giving arise to false pregnancy results. Gestational trophoblastic disease like Hydatidiform moles also known as molar pregnancy can cause high levels of HCG in your body even when you are not pregnant.
Though HCG levels can be considered as a benchmark level to monitor your pregnancy in the initial stages, it is however prudent to depend on the ultrasound reports since HCG levels are known to vary from person to person. If you are undergoing fertility treatments to get pregnant, then your HCG levels will be slightly higher because of the HCG injection that you will receive as a part of the treatment. Since the hormone takes about 5 – 10 days to clear out of the system, it would be best to wait for a few days before doing a home pregnancy test or urine test.
HCG hormone has a very important role during the pregnancy. It is responsible for maintaining the corpus luteum during the pregnancy. It also causes the corpus luteum to secrete the hormone progesterone. Progesterone helps to layer the uterus lining with thick lining of blood vessels and capillaries to strengthen for the growing fetus.