HCG blood test

The human chorionic gonadotropin (hCG) is a special hormonal protein produced by the membranes of the developing embryo after successful implantation in the uterus. It is normally detected in the blood and urine only in pregnant women. hCG consists of two subunits: alpha and beta. To monitor pregnancy, β-hCG tests are performed.

hCG analysis during pregnancy

This hormone can be detected in the blood of a pregnant woman as early as the 6th or 8th day after conception (in urine - 1 to 2 days later). In the early stages and up to the second trimester, it plays an important role in the production of hormones necessary for the proper course of pregnancy.

A blood test for hCG also allows for the diagnosis of multiple pregnancies and monitoring their progression. In addition, its level can indicate possible congenital anomalies in the fetus.

When is a blood test for hCG prescribed?

This test is performed in the following cases:

• To diagnose an early-stage pregnancy;
• To rule out an ectopic pregnancy;
• To monitor the dynamics of the pregnancy;
• As part of prenatal diagnostics to detect fetal malformations;
• To assess the risk of miscarriage.

In addition to pregnancy, blood tests for hCG are used:

• to diagnose amenorrhea;
• In case of suspected tumor, including trophoblastic disease;
• In men, in case of suspected testicular tumor.

The standard for hCG analysis during pregnancy

For the first time, the analysis can be performed between the 6th and 8th day after the estimated conception, but the most accurate results are obtained between the 11th and 12th day. It is important that the hCG level rises dynamically. The peak concentration occurs between the 8th and 11th week of pregnancy, after which it begins to decrease.

The doctor compares the test results with the norm chart, which indicates the hCG level at each term of pregnancy.

Differences in hCG in natural conception and IVF

In natural conception, the hCG level evolves in a standardized manner, starting from the implantation of the embryo and increasing every 48 hours during the first weeks of pregnancy. In contrast, in the case of in vitro fertilization (IVF), IVF with egg donation, or IVF with double donation, the hCG level may evolve differently:

• IVF (with own eggs): hCG levels may be slightly higher during the first weeks of pregnancy due to prescribed hormonal support (progesterone and estrogens).
• IVF with egg donation: hCG levels may be lower, especially in the first days following implantation, as the receptivity of the endometrium may vary.
• IVF with double donation: the dynamics of hCG is similar to that of conventional IVF, but differences may be related to the physical characteristics of the recipient.

Despite possible variations, the growth dynamics of hCG in all types of pregnancy (natural conception and IVF) should correspond to standard norms. That is why it is recommended to carry out dynamic monitoring of hCG levels and additional examinations in case of deviations.

Deviations from the norm

High hCG levels may indicate

• multiple pregnancy
• Genetic anomalies of the fetus;
• Complications associated with diabetes mellitus.
• cirrhosis and other intestinal diseases
• gestational trophoblastic disease

A decrease in hCG levels may be associated with complications related to diabetes mellitus:

In some cases, a decrease in hCG levels is not a pathology but is due to individual characteristics of the organism. For example, in some women, hormone levels may increase more slowly without negative consequences for the pregnancy. It is also possible for hCG levels to fluctuate naturally depending on the woman's metabolism and hormonal context.

However, a decrease may warn of:

• A risk of placental detachment;
• Fetal death;
• Spontaneous abortion;
• Absence of an embryo in the fetal egg.

Sometimes, the low hormone level is explained by an incorrect calculation of the conception date. To ensure the accuracy of the diagnosis, a comprehensive examination is recommended, including an ultrasound of the uterus and fetus, a new determination of hCG levels over time, as well as tests for progesterone and other hormones influencing pregnancy.

Variations in hCG levels in men

In men, the normal hCG level should be less than 5 mUI/ml. However, small fluctuations may be observed with intense physical activity, hormonal changes, or as a result of taking certain medications. A slight increase is not always a sign of pathology but requires further observation as it may indicate:

• trophoblastic tumors;
• Testicular tumors (seminomas and non-seminomatous tumors);
• gastrointestinal, pulmonary, or hepatic tumors;
• hormonal tumors of the pituitary gland.

In the case of suspected oncological processes, hCG analysis in men is one of the markers for the diagnosis and monitoring of disease dynamics.

Where to perform an hCG test?

You can perform an hCG analysis during pregnancy at the "Natuvitro" clinic and receive advice from a gynecologist-obstetrician. Experienced specialists will help you interpret the study results and, if necessary, will prescribe additional examinations and consultations.