Human chorionic gonadotropin (hCG) or the pregnancy
hormone is only produced during pregnancy by the developing
placenta. HCG levels rise daily, and there is a large
variance to what is considered normal for any given
time of pregnancy, as reflected in the chart below.
Normal hCG Levels in Pregnancy
These numbers serve as a guideline and caution should
be used in not making too much of hCG numbers. It
is not always the level that matters but the change
in the level.
| Gestational
week (LMP) |
hCG
level (mIU/ml) |
| Week
3 |
5-50 |
| Week
4 |
5-426 |
| Week
5 |
18-7,340 |
| Week
6 |
1,080-56,500 |
| Weeks
7-8 |
7,650-229,000 |
| Weeks
9-12 |
25,700-288,000 |
| Weeks
13-16 |
13,000-254,000 |
| Weeks
17-24 (second trimester) |
4,060-165,400 |
| Weeks
25-40 (third trimester) |
3,640-117,000 |
| Non-pregnant |
55-200 ng/ml |
Pregnancy
Test
• Home pregnancy test is qualitative i.e.
you are informed if there is hCG present in your
urine. It is not quantitative so it doesn't tell
you how much of hCG is present.
• Women who test early sometimes show negative
results (because of low levels of hCG) but they
are actually pregnant. As a result most home pregnancy
kits come two to a package.
• A urine test can be performed 12-14 days
after conception. If you test early and your results
show negative, but if your periods have not begun
about 10 days to two weeks after you are due, repeat
the test.
• For the test to be positive a certain minimum
amount of hCG should be present in the urine. The
first urine in the morning has the highest concentration
of this hormone so it does make sense to do the
test in the morning. Done according to the accompanying
instructions, home pregnancy tests are very accurate,
even when performed in the early part of pregnancy.
• Blood test is quantitative i.e. it measures
the actual amount of hCG in your blood stream.
• If test is performed as early as 8-11 days
after ovulation, the presence of hCG can be detected
indicating a positive outcome.
In
situations where medical assistance
was necessary for pregnancy, your doctor
will want to conduct more tests some
days later to monitor hCG levels. |
|
| Reasons
behind Low HCG level |
Reasons
behind High HCG level |
| There
was a miscalculation in dating the pregnancy |
Again,
due to miscalculation of dating the pregnancy |
| There
is a possible miscarriage or blighted ovum |
Multiple
pregnancy |
| Ectopic
pregnancy |
Molar pregnancy |
More on HCG
• Normal levels vary from one pregnant woman
to another.
• HCG is detectable throughout pregnancy and
for several weeks after delivery. Pregnancy is generally
healthy if hCG level doubles almost every other day
for the first 60-80 days of pregnancy.
• When you are pregnant this hormone will trigger
the production of another hormone, progesterone which
is responsible for the thickening of the uterine lining.
With hCG absent in the case of the non-pregnant woman,
the uterus lining will shed and a new menstrual cycle
will begin.
• Generally the HCG level tends to double every
2-3 days in early pregnancy. Statistically in about
85% of normal pregnancies the level is known to double
every 72 hours.
• The level of this hormone peaks around 8th-12th
week of pregnancy and then tapers off and remains
at lower levels for the rest of the pregnancy period.
• Low levels of hCG can result in a perfectly
healthy baby. An ultrasound after 5-6 weeks gestation
is more accurate than using hCG numbers.
• HCG level of less than 5mlU/ml is considered
negative for pregnancy and any figure about 25mlU/ml
is considered positive for pregnancy.
• In twin pregnancies a higher level of HCG
occurs on a given day of pregnancy compared to singleton
pregnancy.
• Since hCG levels can vary greatly, hCG levels
should not be used to date a pregnancy.
• It is imperative to not rely on the values
shown on the chart to determine if your pregnancy
is viable, single, multiple etc. Always check with
your doctor about your own levels.
• Medications such as antibiotics, pain relievers,
contraception etc should not have any effect on a
test that measures hCG. However medications containing
hCG can interfere with the result.
