Testing is a mandatory procedure that every pregnant woman goes through. And of course, having received a leaflet with the results, she always tries to understand - well, what’s there, is everything all right? But alas, in addition to numbers, the results contain only obscure abbreviations. HCG, MoM, RaRR-A, ACE - all this says little to an uninitiated person. Let's try to deal with some of them.
Chorionic gonadotropin - what is it?
Under the abbreviation hCG is the human chorionic gonadotropin - a hormone that normally is produced only in a pregnant woman. The fertilized egg begins to produce it, and later, after the trophoblast is formed, its tissue. By the way, it is his appearance in the urine that makes the pregnancy test respond.
The level of hCG can be an indicator of many pathologies of the mother and fetus, while it is either significantly reduced or significantly exceeds the norm. In the event that deviations from it are insignificant, it has practically no diagnostic value.
MoM - what is it
The abbreviation MoM comes from the English multiple of median, or, when translated into Russian, "multiple of the median." The median in gynecology is the average value of a particular indicator at a specific gestational age. MoM is a coefficient that allows you to evaluate how much the results of analyzes of a particular woman deviate from the average. MoM is calculated by the formula: the value of the indicator is divided by the median (average value for the gestational age). MoM does not have its own unit of measurement, since both the patient’s indicators and the median are calculated in the same. Thus, MoM is an individual value for each woman. If it is about unity, then the patient's indicators are close to the average norm. If we consider the hCG, MoM (norm) indicator during pregnancy for it ranges from 0.5 to 2. This value is calculated by special programs that, in addition to arithmetic calculations, also take into account the individual characteristics of a woman (smoking, weight, race). That is why in different laboratories the values of MoM may vary. Deviations of hCG MoM from normal values can signal serious violations both in the development of the fetus and in the condition of the mother.
HCG Functions
Chorionic gonadotropin is a hormone of pregnancy. It starts the processes necessary for its normal development. Thanks to it, regression of the corpus luteum is prevented and the synthesis of progesterone and estrogen that preserves pregnancy is stimulated. In the future, this will provide the placenta. Another important function of hCG is the stimulation of Leydig cells synthesizing testosterone in the male fetus, which, in turn, contributes to the formation of male genital organs.
Chorionic gonadotropin consists of alpha and beta units, and if alpha-hCG in structure differs little from the structural units of the hormones FSH, TTG, beta-hCG (MoM) is unique. That is why beta-hCG is of diagnostic value. In plasma, it is determined immediately after the fertilized egg invades the endometrium, that is, approximately 9 days after ovulation. Normally, the concentration of hCG doubles every two days, reaching a maximum concentration (50,000-100,000 IU / L) by 10 weeks of gestation. After that, for 8 weeks it decreases almost by half, then remaining stable until the end of pregnancy. However, at a later date, a new rise in hCG values may be recorded. And although this was not previously considered a deviation from the norm, the modern approach requires the elimination of placental insufficiency in the Rh conflict, which can cause increased MyCG hCG. After childbirth or uncomplicated abortion in plasma and urine, hCG should not be detected after 7 days.
When analysis is scheduled
HCG analysis (MoM) can be prescribed in the following cases:
- for diagnosis in early pregnancy;
- when monitoring the course of pregnancy;
- to exclude an ectopic pregnancy;
- to evaluate the fullness of artificial abortion;
- if you suspect a missed pregnancy or the threat of miscarriage;
- as part of a triple analysis (with ACE and estriol) for early diagnosis of fetal malformations;
- with amenorrhea (absence of menstruation);
- in men, hCG analysis is done in the diagnosis of testicular tumors.
HCG in MoM for weeks
In different laboratories, different standards for the indicators of this hormone can be set, so the figures given are not a standard. However, in almost all laboratories, the hCG norm in MoM does not go beyond the interval from 0.5 to 2. The table shows the hCG norms from conception, and not from the period of the last menstruation.
Duration (weeks) | HCG honey / ml |
12 | 25 - 30 |
2 - 3 | 1500 - 5000 |
3 to 4 | 10,000 - 30,000 |
4 - 5 | 20,000 - 100,000 |
5 - 6 | 50,000 - 200,000 |
6 - 7 | 50,000 - 200,000 |
7 - 8 | 20,000 - 200,000 |
8 - 9 | 20,000 - 100,000 |
9 - 10 | 20,000 - 95,000 |
11 - 12 | 20,000 - 90,000 |
13-14 | 15,000 - 60,000 |
15 - 25 | 10,000 - 35,000 |
26 - 37 | 10,000 - 60,000 |
When hCG is elevated
The following factors can cause a rise in hCG levels:
- multiple pregnancy;
- endocrine disorders including diabetes;
- fetal malformations (chromosomal abnormalities);
- trophoblastic tumors;
- hCG for therapeutic purposes.
Reasons for Lowered HCG
A decrease in hCG may cause:
- ectopic pregnancy;
- threatening abortion or missed pregnancy;
- antenatal fetal death ;
- chromosomal abnormalities.
HCG in the diagnosis of fetal abnormalities
The current level of medicine allows us to determine abnormalities in the development of the fetus at fairly early stages. An important role in this is played by the study of the level of hCG (MoM). To date, the optimal terms of research have been worked out, which every woman expecting a baby must undergo in order to identify pathological changes in time during pregnancy. They include several indicators. In the first trimester of pregnancy (10-14 weeks), these are ultrasound and laboratory tests of the levels of hCG, PAPP-A hormones. At later dates, in the second trimester (16-18 weeks), in addition to ultrasound, a triple test is performed (AFP, hCG, estriol). The data from these studies are highly likely to assess the possibility of developing fetal pathologies and the risk of chromosomal abnormalities. All forecasts are carried out taking into account individual characteristics - the mother's age, her weight, risks caused by bad habits, pathologies in children born in past pregnancies.
Interpretation of screening results
Unfortunately, in some cases, the results are far from indicators that are considered normal hCG, MoM during pregnancy. If the deviations are minor, then this may not be taken into account as a sign of pathology. However, if the results of the study, against the background of a low level of other markers, show values that significantly exceed hCG 2 MoM, this may indicate the presence of such a chromosomal pathology as Down syndrome in the fetus. Genetic abnormalities such as Edwards or Patau syndromes may be indicated by decreased levels of hCG and other markers. Turner syndrome can be suspected with even levels of hCG against the background of a decrease in other markers. In addition, significant abnormalities in the results of the screening performed may indicate neural tube and heart defects.
If such deviations are detected, an invasive diagnosis is performed to clarify the diagnosis. Depending on the period, the following examinations can be prescribed:
- chorionic biopsy;
- amniocentesis;
- cordocentesis.
In addition, in all disputed cases, consultation with a geneticist is necessary.
HCG during ectopic pregnancy
In addition to abnormalities in the development of the fetus, β-hCG (free), MoM are also indicators illustrating maternal health. One of the dangerous emergency conditions that can be diagnosed in time and, therefore, take action, is an ectopic pregnancy. This happens when a fertilized egg is not attached to the inner layer of the uterus (endometrium), but in the cavity of the fallopian tubes, ovaries, intestines. The danger of this pathology is that an ectopic pregnancy is inevitably interrupted, and this process is accompanied by severe internal bleeding, which can be very difficult to stop. It is possible to detect an ectopic pregnancy if an ultrasound scan is performed in a timely manner and its results are compared with serum hCG indices. The fact is that a fertilized egg, occupying a place not intended by nature, experiences significant difficulties and, as a result, trophoblast produces much less gonadotropin. In the event that the analysis indicators show an extremely slow increase in hCG that does not correspond to the gestational age, an ultrasound scan is prescribed using a vaginal sensor. Typically, this procedure allows you to find a fetal egg outside the uterus, which will confirm an ectopic pregnancy and will allow you to terminate it in time, without waiting for complications.
Frozen pregnancy
It happens that after a pregnancy test has given a positive result, its symptoms do not occur or end abruptly. In this case, the embryo dies, but there is no miscarriage for some reason. This point can be revealed if, in the analysis made, the hCG indices not only cease to grow, but also begin to decline. After an ultrasound scan, you can verify that the embryo has no heartbeat. Sometimes an ultrasound shows only an empty fetal egg. These changes are called missed pregnancies. Most of them develop for up to ten weeks. The causes may be the following conditions:
- chromosomal pathologies;
- infections of the mother's body (most often endometritis);
- defects associated with the coagulation system of the mother (thrombophilia);
- anatomical defects in the structure of the uterus.
In case of detection of a frozen pregnancy for medical reasons, a medical abortion or curettage of the uterus will be performed. In the event that a frozen pregnancy is diagnosed in a woman more than two times, the couple is recommended to be examined to identify the objective reasons for this.
Bubble drift
Sometimes, after fertilization, a “loss” of the female part of the genome may occur, that is, instead of an equal number of chromosomes from the mother and father in the fetal egg, only the male genome remains. In this case, a condition similar to pregnancy can be observed, but only the father’s chromosomes are present in the zygote (fertilized egg). This condition is called complete cystic drift. In the case of a partial egg, it retains its genetic information, but the number of father’s chromosomes doubles. Since they are responsible for the trophoblast, the levels of the hCG hormone are growing rapidly. Bubble drift is dangerous not only spontaneous miscarriage, since the development of a normal pregnancy with it is impossible. The main danger lies in the fact that such a “stimulated” trophoblast is introduced into the uterine wall, growing outside it, and over time it can degenerate into a malignant tumor.
Suspicion of bladder drift can be with the following symptoms:
- uterine bleeding in the early stages;
- excruciating vomiting;
- the size of the uterus does not correspond to the term (it is much larger);
- weight loss, palpitations, tremor of the fingers are sometimes possible.
The appearance of such signs requires medical attention, an ultrasound scan and monitoring of serum hCG levels. Exceeding several times the figure of 500,000 IU / L, which is the maximum during normal pregnancy, requires a more careful examination.
Thus, careful attention to the level of hCG, MoM allows you to diagnose many pathological changes in the body of a woman and the fetus in the early stages. And therefore, in time to take the necessary measures.