HCG - Facts

HCG - Facts
Facts about hCG


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Q: What is hCG and what does it do?
A: Human Chorionic Gonadotropin (hCG) is the "pregnancy hormone." It is produced by the early
placenta and keeps the corpus luteum producing progesterone when conception occurs. It can be
detected both in the urine and in the blood. Home Pregnancy Tests (HPTs) measure the urine HCG
qualitatively, which mean results are either "positive" or "negative." Around the time of the first
missed period (14+ days after ovulation), about 98% of home pregnancy tests are usually positive.
The blood hCG test measures the HCG quantitatively, which means you get a number for the test. The
blood hCG is much more sensitive than a urine HPT, and it can detect pregnancy as early as 10 days
after fertilization.
Other than for the diagnosis of pregnancy, hCG is also often monitored over time for reasons such as
monitoring after a miscarriage, monitoring an ectopic pregnancy, and after a condition called
"H.mole."
Other facts about hCG:


hCG is first found in the blood as early as 7-8 days after ovulation

Pregnant women usually attain serum concentrations of 10-50 mIU in the 7-8 days following conception

An hCG of less than 5 is usually negative, over 25 usually positive

HCG monitoring is more useful before the fetal heart is seen (before 6-7 weeks after LMP), ususally
to rule out an ectopic pregnancy or an early miscarriage

In an ectopic pregnancy, hCG increases at lower rates than in a normal pregnancy

At hCG levels above 1,000-1,500, vaginal sonography usually identifies the presence of an
intrauterine pregnancy

Within the first 2-4 weeks after fertilization, hCG usually doubles every 48-72 hours

Below 1,200 IU, hCG usually doubles every 48-72 hours

From 1,200-6,000 IU, the hCG usually takes 72-96 hours to double

Above 6,000 IU, the hCG often takes over four days to double

More than two in three normal pregnancies have a doubling of the hCG every 72 hours

IMPORTANT: There is a wide variation of normal hCG levels. An hCG that does not double every two to
three days does not necessarily indicate a problem

A maximum is usually reached by the 10th or 11th week.

After 10 weeks or so, hCG normally decreases

Normal hCG values vary up to 20 times between different pregnancies

A single hCG value doesn't give enough information about the viability of the pregnancy

Pregnancies that will miscarry and ectopic (tubal) pregnancies are likely to show lower levels and
slower rises, but often have normal levels initially

Some normal pregnancies will have quite low levels of hCG -- and deliver perfect babies

Once fetal activity has been detected by ultrasound in a normal patient population, chances of
normal delivery are about 95%

Normal levels of hCG can vary tremendously. After 5-6 weeks of pregnancy, sonogram findings are much
more predictive of pregnancy outcome than are HCG levels. Once the fetal heart rate is seen, most
doctors will monitor the fetal heart rate rather than drawing hCG

After hCG injections (Profasi, Pregnyl) to trigger ovulation or to lengthen the luteal phase, trace
amounts of hCG can remain in the body as long as 14 days or longer after the last hCG injection.
This may give a false positive on a pregnancy test. Two consecutive quantitative hCG beta blood
tests can determine whether the hCG is from an injection or pregnancy. If the hCG level increases by
the second test, you are likely pregnant