In vitro fertilization - for many couples, this may be the last chance to have such a desired child. One of the most important indicators that pregnancy is developing 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.
ECO - What's the point
Of course, everyone knows that in order to have a child, a sperm cell (male sex cell) must meet and fertilize an egg (female sex cell). After that, it is introduced into the mucous membrane of the uterus, undergoes a series of changes that occur 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, spermatozoa are not able to fertilize an egg on their own, or an already fertilized egg cannot reach the uterus or be introduced into it. But atThis woman is quite capable of bearing a child. And then the doctors come into play. Taking the germ 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. At the same time, during the procedure, not one, but two embryos are introduced at once. This increases the chances that pregnancy will still occur. However, there is a high risk that you will have to repeat this procedure several times. It happens that the embryo takes root not even on the second, but on the fourth or fifth attempt. The abbreviation DPP refers to how many days have passed since the introduction of the embryo. This date is very important, to make sure that the pregnancy has come, you need to wait for 14 DPO. 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 already fertilized, the appearance of this hormone in a blood test or in the urine means that the embryo was successfully implanted. It is believed that pregnancy has occurred if hCG at 14 DPP of five days (embryos that were introduced on the fifth day after fertilization occurred) is at least 100 mIU / l. If the indicators are 25 mIU / l and below,then, most likely, the procedure will have to be repeated. However, low values of this analysis can also be in the event that not enough time has passed after the introduction of the embryo, for example, hCG is determined at 12 DPP.
What HCG shows
Horionic gonadotropin is also called the hormone of pregnancy. 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 is introduced into the uterine mucosa. After that, its concentration begins to grow rapidly. In the normal course of pregnancy, it doubles every two days. The maximum hCG (DPP) is recorded at the tenth week. After that, 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 determining chorionic gonadotropin
For most women after successful IVF, changes in hCG levels begin to be tracked as early as 9-14 days. In order to identify its appearance, it is not even necessary to donate blood. Pregnancy tests work on the principle of detecting its presence in the urine. Of course they don'tindicate the exact numbers and amounts of hCG on the DPP of five days or three days, but its very presence with a high degree of probability indicates a pregnancy. To get a more accurate result, a woman donates blood. If during a normal pregnancy, blood for hormones is donated 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 implantation of the embryo. The results obtained are compared with a table that shows the minimum, maximum and average values of hCG at a certain period of DPP.
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 week of pregnancy. There are also tables showing indicators of the increase in the level of the hCG hormone by day. They are most relevant for those who have undergone IVF. The table below shows only the average day post-implantation (DPO) values for embryos that were implanted 3 and 5 days post-fertilization.
DPP |
three days |
five days |
| 2 | - | 4 |
| 3 | - | 7 |
| 4 | 4 | 11 |
| 5 | 7 | 18 |
| 6 | 11 | 28 |
| 7 | 18 | 45 |
| 8 | 28 | 72 |
| 9 | 45 | 105 |
| 10 | 73 | 160 |
| 11 | 105 | 260 |
| 12 | 160 | 410 |
| 13 | 260 | 650 |
| 14 | 410 | 980 |
| 15 | 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 |
| 29 | 22600 | 27200 |
| 30 | 24000 | 31000 |
| 31 | 27200 | 36000 |
| 32 | 31000 | 39500 |
| 33 | 36000 | 45000 |
| 34 | 39500 | 51000 |
| 35 | 45000 | 58000 |
| 36 | 51000 | 62000 |
As you can see, hCG at 7 DPP five days is 45 mIU / l, but normally its values 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 increasing hCG
As already mentioned, HCG is not onlyan indicator that pregnancy has occurred, but also allows you to control its course. In the event that the level of this hormone is not much outside the normal range, then this is not given much importance, but if the hCG DPP values do not correspond significantly, then this can be a signal of the presence of serious pathologies of both the mother and the fetus. A significant increase in this indicator can lead to:
- Chromosomal abnormalities in fetal development (Down syndrome);
- trophoblastic tumors;
- endocrine disorders (diabetes mellitus);
- taking medications containing gestagens;
- multiple pregnancy.
Reasons for a decrease in hCG
Low levels of charotic gonadotropin can be registered in the following cases:
- threatened abortion;
- missed pregnancy;
- fetal malformations;
- antenatal fetal death;
- prolongation of pregnancy;
- placental insufficiency;
- ectopic pregnancy.
Elevated HCG on DPP. Twins
In IVF, in order to increase a woman's chances of becoming pregnant, two embryos are implanted at once, but this often does not guarantee the success of the procedure. However, there are also such precedents when both take root at once. In this case, hCG levels can increase by 2-3 times. This is due to the fact that it is produced not by one placenta, as is the case with a singleton pregnancy, but by two at once. For example, if the level of hCG at 16 DPP five days averages 1960 mIU / l, then for twins it is norm althe indicator will be 3920 mIU / l and above.
HCG indicator in the diagnosis of fetal anomalies
Of course, pregnancy is an important and expected event in the life of any woman, but it happens that it brings not only joy, but also experiences. Against the background of stress, ecology and other factors that do not have the best effect on the emerging life, there is a risk of developing pathologies. The modern level of medicine allows many of them to be diagnosed and even corrected at an early stage. It is for this that mandatory screenings are carried out in the first and second trimesters of pregnancy. Screening for the first trimester, which is usually carried out at 10-14 weeks, includes ultrasound and monitoring of the levels of the hormones hCG and PAPP-A. 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 significantly exceeds the norm, it is highly likely that the fetus has Down syndrome. Edwards or Patau syndromes may be suspected when all three markers are low. Relatively normal human chorionic gonadotropin levels with low AFP and estriol may indicate Turner syndrome.
All predictions are made based on the individual characteristics of the ongoing pregnancy - the age of the mother, her weight, the presence of bad habits, concomitant pathologies, diseases in children born in previouspregnancy. If the examination revealed even minor deviations from the norm, the woman is required to be referred to a genetics consultation.
How to get tested
To test for hCG, you need to donate blood 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 during the day, you need to refrain from eating for at least 6 hours. In the event that you are taking any drugs containing hormones ("Pregnil", "Horagon"), you need to warn your doctor about this in advance.
In order for a laboratory test to be more informative, it is better to do it no earlier than 3-5 days after a missed period. In the case of IVF, the diagnostics carried out on the 14th day after the procedure will have the most accurate data.
