Many pregnant women are confused about hCG levels and what they mean. Human Chorionic Gonadotrophin or, hCG for short, is the hormone unique to pregnancy. It can be detected in urine and blood. hCG can be very important, especially hCG levels in early pregnancy, to women who are pregnant, but not very interesting to those who aren’t.

What is hCG?

hCG is the hormone which is responsible for most early pregnancy symptoms. Those signs and symptoms which make women question if perhaps they are pregnant. Breast tenderness, feeling a little emotional, nausea and fatigue – they’re all due to hCG levels.

Where does hCG come from?

hCG is produced by the cells which will eventually become the placenta. Long before it is fully formed, the early placental tissue sends a message to the ovarian follicle where the egg was released. This area is called the corpus luteum. It plays an important role in influencing the production of oestrogen and progesterone. These hormones are responsible for building up a rich bloody lining in the uterus to feed the developing embryo before the placenta has formed. Without this, the chances of the embryo surviving would be pretty slim. Problems with the function of the corpus luteum may contribute to fertility problems and early miscarriage.

When does hCG cause symptoms?

It takes around 2 weeks after conception for hCG to be detected in a hCG pregnancy test. Low levels of hCG may be detected in a woman’s blood 8-11 days after conception. hCG levels in early pregnancy are at their highest towards the end of the first trimester, before they gradually decline over the rest of the pregnancy. hCG levels can vary at different times of the day, and from week to week. 

 Some women seem to be very sensitive to the effects of hCG and from very early pregnancy, feel symptoms. hCG levels can vary between individual women and if they are carrying more than one embryo. Check here for more information on hCG levels.

 Generally a woman’s hCG levels double every 72 hours. hCG levels in pregnancy reach their peak in the first 8-11 weeks of pregnancy and then tend to level off for the next two trimesters. This is why, in the first trimester (3 months) of pregnancy, symptoms can be so much stronger and intense.

What’s good to understand about hCG?

• Levels of hCG in blood can give some general insights into the pregnancy and baby’s health.
•  High levels of hCG can indicate the presence of more than one baby e.g. twins or triplets. 
•  Low levels of hCG can indicate pregnancy loss or risk of miscarriage.
• Low levels of hCG can also indicate an ectopic pregnancy or problems with the pregnancy and perhaps, the baby’s growth and/or development. 
•  hCG levels can also be affected when there is abnormal tissue growth in the ovaries or uterus and some types of gynaecological cancers. 

How can I tell if I’m producing hCG?

Even the cheapest home pregnancy test is sensitive enough to detect hCG. However, it won’t actually give you any idea of what your hCG levels in early pregnancy are. 

hCG levels Chart

Average blood levels of hCG during pregnancy

For more information check here

Remember, these numbers are a guide. Every woman and her pregnancy are unique and what is normal for one may not be for another. If you have any concerns about your individual hCG readings, it’s important to see your health care professional. 

What do I need to know about hCG?

• Most pregnant women don’t know what their individual hCG levels in pregnancy are, unless they’ve had fertility assistance.
• A pregnancy ultrasound gives a more accurate prediction of gestational age than one isolated hCG reading.
• For real benefits, a series of hCG blood tests are taken a couple of days apart and readings are compared.
• hCG levels are not indicative of the strength, intelligence or gender of the baby. They are simply a marker for whether sufficiently high levels of hCG have been detected and then measured.

What can a high hCG level mean?

There are a few reasons why a woman’s hCG can be particularly high - miscalculation of pregnancy dates, carrying a multiple pregnancy or very rarely, a molar pregnancy or a placental tumour. It is common for health care providers, if concerned, to recommend repeat testing with 48-72 hours to check for changes in the level of hCG.

What can a low hCG level mean?

Perhaps it’s too early in the pregnancy for levels of hCG to be high. It’s easy to miscalculate gestational age, especially for women who have irregular menstrual cycles. A blighted ovum, miscarriage or ectopic pregnancy can also result in low hCG levels. 

FAQ

Can I have a false negative pregnancy test?

It’s possible to have a false negative pregnancy test but it’s virtually impossible to have a false positive pregnancy test. Doing a test too early can lead to a false negative result. 

What should I know about my hCG readings?

Even if you do find out your hCG level, don’t make too much of it. A low reading of hCG can still lead to a healthy pregnancy and baby.

Can I tell how far I am along from my hCG tests?

Dating a pregnancy or gestation from hCG readings alone isn’t ideal. This is because there is such a big variation between women, and what is considered “normal”.

Written and reviewed by Jane Barry, midwife and child health nurse on 12/01/20