Despite the high level of popularity of IVF, most people are not sufficiently informed about the nuances of its implementation. One of the most important questions at the planning stage is how many embryos are better to implant in IVF. Despite some difficulties in carrying out a multiple pregnancy, a significant number of patients prefer to carry two or more embryos, due to the fear of not having a result when one is implanted. Which criteria and nuances to pay attention to in the choice between single and multiple pregnancies - we will consider further.
RISKS IN MULTIPLE PREGNANCIES
For a person, the physiological norm is a single-federal pregnancy. Carrying two or more children often involves a number of risks, as evidenced by the numerous feedback from practitioners. The likelihood of premature births in multiple pregnancies is particularly high. In addition, the following options for complications are possible:
- Pelvic or transverse preposition, which is found in 50% of multiple pregnancies cases. Incorrect fetal position complicates or completely excludes natural delivery. When this is done, it is highly probable that the child will suffer a birth injury.
- Increased risk of developing gestose in the late stages of embryo. In most cases, this complication leads to detachment of the placenta and hypoxia in the fetus.
- Transfusion syndrome. Transfusion syndrome is one of the common causes of spontaneous termination of multiple pregnancy. The pathology arises against the background of multiple pregnancies, when both fetuses share the same placenta, resulting in hemodynamic imbalance.
- Pathologies of development. If the number of embryos in IVF is two or more, there is a risk of insignificant risk of developing pathologies of the intrauterine development, which is due to the lack of important trace elements necessary for fetal formation.
Deciding how many embryos to implant in IVF, the overall health of the mother is taken into account. Carrying out a multiple pregnancy is fraught with risk for the woman, because the body needs to withstand double loads. In some cases, pregnancy is accompanied by various complications, including anaemia, gestosis, high blood pressure, preeclampsia.
THE IVF PRACTICE, WHICH WAS APPLIED SEVERAL YEARS AGO
The question of how many embryos should be implanted in IVF has become relevant relatively recently. Previously, there was no need to consider it as such. This approach was due to the lack of methods and ways to determine the viability and absence of pathologies in the embryo.
A few years ago, when the IVF procedure was positioned as an innovation, the practice of implanting several embryos was common. Sometimes the number of embryos was about 20. This approach was due to the high risk of killing more embryos. When everything was fixed, the problems of embryos and births were solved on the move.
A little later, an alternative option appeared. When three or more embryos were attached, the woman was asked to undergo a reduction procedure, which consisted of selectively removing several embryos. There were, however, a number of risks:
- damage or death of the remaining fetal egg;
- infection of the mother's reproductive system;
- damage to uterine tissue;
- increased risk of spontaneous early termination of pregnancy.
In order to minimize the risks to the future mother and child, the question of how many embryos are implanted in IVF, is decided before, not after, the procedure.
HOW TO INCREASE THE CHANCES OF EMBRYO ATTACHMENT
The absence of a positive result after the transfer procedure may be the result of aneuplodia: the presence of chromosomal disorders in the genetic material of the embryo. According to statistics, the risks increase in proportion to the age of the woman. Accordingly, how many embryos are transferred in IVF also depends on the age of the expectant mother. The higher they are, the greater the risk percentage:
- at the age of 35, out of three healthy embryos, one is anaemic;
- after 35 years of age, two of the three embryos are more anaemic;
- before the age of 40, five out of six embryos have abnormalities;
- after 44 years, only one embryo out of ten has no chromosomal abnormalities.
In In Vitro Fertilization the healthiest embryo with no abnormalities is selected for transfer.
To determine their viability and to decide how many embryos to transfer in IVF, a pre-implantation genetic screening procedure is performed. Its essence is as follows: after the fifth day of development, a trophytoderm is taken to detect chromosomal abnormalities. The procedure is completely safe and allows to determine a completely healthy embryo.
As the undeniable advantages of pre-implantation genetic screening can be mentioned a number of the following:
- an embryo with the highest viability will be selected for implantation;
- the chances of pregnancy from the first time are multiplied;
- it is possible to select a tedious number of embryos, i.e. the possibility of multiple pregnancies is excluded;
- minimizing the risk of giving birth to a child with genetic pathologies.
The genetic screening procedure also makes it possible to identify pathologies that may manifest themselves later in the development of the embryo or lack thereof.
HOW MANY EMBRYOS ARE RECOMMENDED FOR IMPLANTATION
How many embryos can be implanted in IVF depends on many factors. For more information, it is recommended to read the specialists' answers to the questions, which are especially often asked by clients who want to have a baby by In Vitro Fertilization:
- What are the chances of success of In Vitro Fertilization and successful outcome of pregnancy? If a genetic screening procedure has been performed, which resulted in the selection of the healthiest embryo, the chances of a positive result are more than 60%. When two embryos are implanted without screening, the success rate varies between 65.
- How many embryos are there in IVF and what is the probability of multiple pregnancy? When two embryos are implanted, the probability of twins being born is about 30%. If one embryo is selected for the procedure, the chances of twins also remain, but this happens in 1 out of 100 cases.
- What is the probability of a miscarriage? The risks of spontaneous abortion are present in each IVF case. However, in the case of fetal injection after screening, the probability of miscarriage is no more than 11%, whereas in the case of two without this procedure, it is 20%.
- What is the risk of premature birth? The probability of early delivery in pregnancy through In Vitro Fertilization is low and is no more than 11% in single gestation. In multiple pregnancies, the probability of early birth is slightly higher and is about 30%.
- What will the child's weight be at birth? As a rule, the given indicators are standard. More babies born after IVF procedure weigh about 3.5 kg. If the pregnancy was multiple births, the weight of newborns is slightly lower, and more often than not more than 2.7 kg.
- Is the child at risk of developing cerebral palsy? The percentage of risk depends on whether the pre-implantation genetic screening procedure was performed. In this procedure, the probability of diagnosing cerebral palsy is no more than 1/1000. Without it, the risk increases slightly, and is 7.4 per 1000.
Without an individual approach to the situation, it is not possible to determine in advance which measure would be more effective - the implantation of one or two embryos after the screening procedure has been carried out. It is advisable to consult a specialist to obtain answers that are as close as possible to reliable ones. In some cases, two embryos may well be implanted as the likelihood of a successful pregnancy is high. Sometimes a woman should postpone the question of having a second baby a little later.