In vitro fertilization - for many couples this is perhaps the last chance to have such a desired child. One of the most important indicators that pregnancy develops normally is the hCG hormone. DPP - this indicator is also very important in assessing pregnancy after IVF. Let's see what is hidden under these abbreviations.
IVF - what's the point
Of course, everyone knows that in order for a baby to appear, a sperm (male reproductive cell) must meet and fertilize an egg (female reproductive cell). After that, it is introduced into the mucous membrane of the uterus, undergoes a series of changes that take place over nine months, after which a child is born. Often the cause of infertility is the inability to carry out these two processes in vivo. That is, for a number of different reasons, sperm are not able to fertilize an egg on their own, or a fertilized egg cannot reach the uterus or invade it. But at the same time, a woman is quite capable of bearing a child. And then the doctors come in. Taking the sex cells of both parents, they carry out artificial insemination and introduce the resulting embryo into the endometrium. Of course, this description is very schematic. Thus, the process of conception is somewhat simplified, and many couples get a chance.
Dpp
A fertilized egg (embryo) is implanted into the uterus on the 3rd or 5th day after fertilization. Moreover, during the procedure, not one, but two embryos are introduced at once. This increases the chances that the pregnancy still comes. Nevertheless, there is a great risk that you will have to repeat this procedure several times. It happens that the embryo does not even take root from the second, but from the fourth or fifth attempt. The acronym DPP refers to how many days have passed since the embryo was introduced. This date is very important, to make sure that the pregnancy has come, you need to wait 14 DPP. HCG, the level of which is measured precisely at this time, is the main marker of this event.
HCG hormone
Human chorionic gonadotropin (hCG) is normally determined only in the body of a pregnant woman. The egg begins to produce it, but since it enters the body of a woman who is already fertilized, the appearance of this hormone in a blood test or in urine means that the embryo was introduced successfully. It is believed that pregnancy has occurred if hCG at 14 DPP for five days (embryos that were introduced on the fifth day after fertilization) is not less than 100 mIU / L. If the indicators are 25 mIU / L and lower, then most likely the procedure will have to be repeated. However, low values ​​of this analysis can also occur if the time has not passed since the embryo was introduced, for example, determine hCG by 12 DPP.
What shows hCG
Chorionic gonadotropin is also called pregnancy hormone. Immediately after fertilization, it prevents the corpus luteum from regressing and stimulates the synthesis of hormones such as estrogen and progesterone. In the blood serum, hCG is determined immediately after the egg has invaded the uterine mucosa. After that, its concentration begins to grow rapidly. In the normal course of pregnancy, every two days it doubles. The maximum hCG (DPP) is recorded at the tenth week. After this, the level of this hormone gradually decreases over 8 weeks, and then remains stable until delivery.
It should be noted that doctors closely monitor the level of the hormone in the blood serum and the ratio of hCG - DPP also because significant deviations of this indicator from the normal range often become a marker of serious pathologies both in the mother’s body and in the development of the fetus.
Methods for the determination of chorionic gonadotropin
In most women, after successful IVF, changes in hCG levels begin to be tracked as early as 9-14 days. In order to detect its appearance, it is not even necessary to donate blood. Pregnancy tests work on the principle of determining its presence in the urine. Of course, they do not indicate the exact numbers and numbers of hCG on the DPP for five days or three days, but its very presence with a high degree of probability indicates the onset of pregnancy. To get a more accurate result, a woman donates blood. If during normal pregnancy, blood is donated to hormones during screening, which is carried out in the first trimester, then during in vitro fertilization for a more informative picture, gynecologists recommend doing this every 2-3 days after the embryo is introduced. The results are compared with the table, which indicates the minimum, maximum and average values ​​of hCG at a certain period of DFS.
HCG norms
Like all indicators, the level of hCG can vary within certain limits. Most often, the table shows data on fluctuations in its level by weeks of pregnancy. There are also tables showing an increase in the level of hCG hormone by day. They are most relevant for those who undergo IVF. The table below shows only the average values ​​on the day after introduction (DPP) for embryos that were implanted 3 and 5 days after fertilization.
Dpp | three days | five days |
2 | - | 4 |
3 | - | 7 |
4 | 4 | eleven |
5 | 7 | 18 |
6 | eleven | 28 |
7 | 18 | 45 |
eight | 28 | 72 |
9 | 45 | 105 |
10 | 73 | 160 |
eleven | 105 | 260 |
12 | 160 | 410 |
thirteen | 260 | 650 |
fourteen | 410 | 980 |
fifteen | 650 | 1380 |
16 | 980 | 1960 |
17 | 1380 | 2680 |
17 | 1960 | 3550 |
19 | 2680 | 4650 |
20 | 3550 | 6150 |
21 | 4650 | 8160 |
22 | 6150 | 10200 |
23 | 8160 | 11300 |
24 | 10200 | 13600 |
25 | 11300 | 16500 |
26 | 13600 | 19500 |
27 | 16500 | 22600 |
28 | 19500 | 24000 |
29th | 22600 | 27200 |
thirty | 24000 | 31000 |
31 | 27200 | 36000 |
32 | 31000 | 39500 |
33 | 36000 | 45000 |
34 | 39500 | 51000 |
35 | 45000 | 58000 |
36 | 51000 | 62000 |
As you can see, the hCG at 7 DPP for five days is 45 mIU / L, but normally its performance can range from 17 to 65 mIU / L. On the same day, the average for a three-day embryo will be 18, and the normal range will be 8-26 mIU / L.
Reasons for an increase in hCG
As already mentioned, hCG is not only an indicator that pregnancy has occurred, but also allows you to control its course. In the event that the level of this hormone does not go much beyond the norm, then they do not attach much importance to it, but if the hCG DPP indicators do not correspond significantly, this can be a signal that there are serious pathologies of both the mother and the fetus. A significant increase in this indicator can lead to:
- chromosomal abnormalities in the development of the fetus (Down syndrome);
- trophoblastic tumors;
- endocrine disorders (diabetes mellitus);
- taking drugs containing gestagens;
- multiple pregnancy.
Reasons for a decrease in hCG
Low levels of chariotic gonadotropin can be recorded in the following cases:
- threatening abortion;
- frozen pregnancy;
- fetal malformations;
- antenatal fetal death ;
- pregnancy overtaking;
- placental insufficiency;
- ectopic pregnancy.
Increased hCG on the DPP. Twins
With IVF, in order to increase the chances of a woman becoming pregnant, two embryos are implanted at once, but this often does not guarantee the success of the procedure. However, there are such precedents when both take root at once. In this case, hCG indices can grow by 2-3 times. This is due to the fact that it is produced not by one placenta, as it happens with a singleton pregnancy, but two at once. For example, if the hCG level at 16 DPP for five days is an average of 1960 mIU / L, then for twins the normal indicator would be 3920 mIU / L and higher.
HCG in the diagnosis of fetal abnormalities
Of course, pregnancy is an important and expected event in the life of any woman, but it happens that she brings not only joy, but also experiences. Against the background of stresses, ecology and other factors that do not have the best effect on the emerging life, there is a risk of developing pathologies. The current level of medicine allows many of them to diagnose and even adjust in the early stages. That is why mandatory screenings are carried out in the first and second trimester of pregnancy. First trimester screening, which is usually done for 10–14 weeks, includes ultrasound and monitoring the levels of hCG and PAPP-A hormones. Screening of the second trimester is carried out at 16-18 weeks. In it, along with ultrasound, a triple test is performed (hCG, AFP, estriol). The data of the second screening make it possible to determine the presence of pathologies with a high probability. In the event that, against the background of low levels of AFP and estriol, the level of hCG is significantly higher than normal, with a high degree of probability we can suspect the presence of Down syndrome in the fetus. Edwards or Patau syndromes can be suspected with a low level of all three markers. Relatively normal chorionic gonadotropin indices at low AFP and estriol may indicate Turner syndrome.
All forecasts are made based on the individual characteristics of the ongoing pregnancy - the mother’s age, her weight, the presence of bad habits, concomitant pathologies, diseases in children born in previous pregnancies. If the examination revealed even slight deviations from the norm, a woman is necessarily referred to a geneticist for a consultation.
How to take an analysis
An analysis for hCG requires blood donation from a vein. It is better to do this in the morning and strictly on an empty stomach. In the event that you have to take it in the afternoon, you need to refrain from eating at least 6 hours. In the event that you are taking any drugs containing hormones (“Rotted”, “Horagon”), you should warn your doctor about this in advance.
In order for the laboratory study to be more informative, it is better to do it no earlier than 3-5 days after the delay of menstruation. In the case of IVF, the most accurate data will be the diagnosis carried out on the 14th day after the procedure.