Beta HCG test

The beta HCG test is the surest way to confirm an early pregnancyIt is also used to monitor her during the first weeks after conception. Sometimes, however, instead of heralding good news, it indicates an ongoing disease process. When to perform a beta HCG test and how to interpret the results?

What is beta HCG?

Beta HCG, otherwise known as gonadotropiną cosmówkowa, is a hormone produced in the woman's body from the 6th to the 12th day from conception until the end of pregnancy. It therefore allows early diagnosis of pregnancy. Initially, the hormone is produced by the trophoblast, the outer layer of the embryo's cell membrane. Once the embryo has implanted in the uterine wall and the corpus luteum has developed into the placenta, it is the placenta that takes over the secretory function.

It's one of the most important hormones during pregnancy - sustains it and allows it to control its course. Initially, it is responsible for the maintenance of the corpus luteum until it turns into the placenta, and at a later stage of pregnancy it regulates the process, the production of steroid hormones in the foetus. Deviations from the normal concentration of beta HCG in pregnancy may indicate an abnormal course of pregnancy.

The HCG hormone has two subunits - alpha and beta. It is the testing of this second component that gives the best results in the early diagnosis of pregnancy, as it is much more sensitive than the HCG total test.

After conception, the level of this hormone rises at a very rapid rate - in the first trimester, its concentration doubles on average every 48 hours. It reaches its highest values around 8-10 weeks of pregnancy, to then start to decrease until around the 16th week of pregnancy, when the concentration normalises and remains fairly constant until the day of delivery.

Indications for a beta HCG blood test

The beta HCG test can be performed by home or laboratory methods. The home method for determining the concentration of this hormone is the popular a pregnancy test that detects beta HCG in urine. Strip tests, however, have much lower sensitivity and, in addition, the concentration of the hormone in urine is much lower than in blood, so they may not detect pregnancy at an early stage.

Laboratory test checks the beta HCG values in the patient's blood, which is a much more reliable method, especially in the very early stages of pregnancy. Pregnancy strip tests are recommended to be carried out not earlier than 14 days after conception, whereas a laboratory test can indicate pregnancy as early as day 8 after conception[1].

Testing for beta HCG is not only used for early diagnosis of pregnancy and its subsequent control, but also:

  • in diagnostics ectopic pregnancy[2],
  • for confirmation of spontaneous miscarriages[3],
  • in the diagnosis of complications of pregnancy,
  • as a tumour marker (mainly for ovarian cancer).

BHCG is also performed after embryo transfer to check that the embryo has implanted properly in the uterus and, as a result, foreshadows the success of the in vitro procedure.

Beta HCG tests are also used in cases where it is necessary to rule out pregnancy (e.g. when it is a contraindication to medical procedures).

Beta HCG standards - how to read the results?

Pregnancy is said to occur when the beta HCG concentration exceeds 5 mlU/ml. Lower values certainly indicate that the patient is not pregnant.

Beta HCG norms depend on the specific week of pregnancy and are as follows[4]:

  • up to the 3rd week of pregnancy - 5 to 50 mlU/ml,
  • 4th week of pregnancy - 5 to 425 mlU/ml,
  • Week 5 of pregnancy - 18 to 7340 mlU/ml,
  • Week 6 of pregnancy - 1080 to 56500 mlU/l,
  • 7th to 8th week of pregnancy - 7650 to 229000 mlU/ml,
  • 9th to 12th week of pregnancy - 25700 to 288000 mlU/ml,
  • 13th to 16th week of pregnancy - 13300 to 254000 mlU/l,
  • 17th to 24th week of pregnancy - 4060 to 165400 mlU/l,
  • 25th to 40th week of pregnancy - 3640 to 117000 mlU/ml.

Results that deviate from the norm for a given week of pregnancy are an indication for further investigation prenatal diagnosisas they may be indicative of developing abnormalities.

Increased levels of beta HCG However, it is not always indicative of pregnancy. High levels of this hormone in the absence of pregnancy can indicate:

  • ovarian cancer,
  • hypogonadism,
  • miscarriage,
  • ectopic pregnancy.

During pregnancy, deviations from normal HCG beta levels may in turn indicate an abnormal pregnancy.

Beta-HCG concentrations above normal can also indicate a so-called "biochemical pregnancy"[5]which means miscarriage before 6 weeks after fertilisation, i.e. even before implantation of the embryo in the uterine wall. Biochemical pregnancies occur in up to 70% patients, and a significant proportion of the women do not even realise that fertilisation has occurred.

It is customary for a patient to find out that she has had a biochemical pregnancy when she takes a pregnancy test due to a delayed period. The test is positive, but by the time the woman sees the gynaecologist, who orders a blood test for beta HCG levels, the embryo has already been aborted and there is a significant drop in the concentration of this hormone.

Availability and cost of beta HCG testing

Testing of beta HCG levels can be performed at any analytical laboratory. If the patient has a referral from her gynaecologist with her, the test can be performed free of charge within the framework of the National Health Fund.

Test price depends on the pricing policy of the selected facility and the location. The average cost of performing a beta HCG test from blood is between PLN 35 and 50.

Frequently asked questions about the beta HCG test

The beta HCG test arouses a lot of emotion because of the message it can herald. What are the most frequently asked questions about it?

When is the earliest that a beta HCG blood test can be done to detect pregnancy?

A beta HCG determination can detect pregnancy as early as 10 days after conception. However, doctors recommend waiting with the test until the day of the expected menstruation. Then the result is more reliable.

What beta HCG result is an indication of pregnancy?

It is assumed that a result higher than 5 mlU/ml allows a pregnancy to be presumed. However, in order to confirm this, an ultrasound examination is usually carried out in addition or the beta HCG test is repeated after 48 hours to check whether its concentration is increasing.

How do I prepare for the HCG test?

Blood for the beta HCG level test can be drawn at any time. The patient does not need to be fasting.

What can falsify a beta HCG test result?

An increase in chorionic gonadotropin levels does not necessarily indicate pregnancy. However, certain medications can also raise its value. These include:

  • certain antipsychotic drugs (e.g. chlorpromazine),
  • certain antidepressants (Escitalopram)
  • medicines used in the treatment of infertility (Ovitrelle and Pregnyl).

Also during the peri-menopausal period, there is an increase in the concentration of this hormone, which after the end of menopause usually sets at a high

[1] CONNOLLY, AnnaMarie, RYAN, David H., STUEBE, Alison M., et al. Reevaluation of discriminatory and threshold levels for serum β-hCG in early pregnancy. Obstetrics & Gynecology, 2013, vol. 121, no. 1, p. 65-70.

[2] SURAMPUDI, Kameswari et GUNDABATTULA, Sirisha Rao. The role of serum beta hCG in early diagnosis and management strategy of ectopic pregnancy. Journal of clinical and diagnostic research: JCDR, 2016, vol. 10, no. 7, p. QC08.

[3] KAŹMIERCZAK, Wojciech, FIEGLER, Patrycja, KAMIŃSKI, Kazimierz, et al. Usefulness of laboratory tests in the contemporary diagnosis of miscarriage. Ginekologia Praktyczna, vol. 12, no 4, p. 16-20.

[4] SIRIKUNALAI, P., WANAPIRAK, C., SIRICHOTIYAKUL, S., et al. Associations between maternal serum free beta human chorionic gonadotropin (β-hCG) levels and adverse pregnancy outcomes. Journal of Obstetrics and Gynaecology, 2016, vol. 36, no. 2, p. 178-182.

[5] Annan, J. J. K., Gudi, A., Bhide, P., Shah, A., & Homburg, R. (2013). Biochemical pregnancy during assisted conception: a little bit pregnant. Journal of clinical medicine research, 5(4), 269.