In case of a non-developing pregnancy

Approximately half of all early pregnancy losses are due to an error that occurs during the formation of germ cells or at the time of fertilization. As a result of such an error, the embryo receives an abnormal number of chromosomes. This is called a chromosomal abnormality. Usually, chromosomal abnormalities occur by accident. This means that pregnancy loss is not caused by a woman doing something wrong.

Sometimes chromosomal abnormalities can be inherited from parents and lead to repeated pregnancy losses in a couple. This happens when one partner has part of one chromosome attached to the other chromosome. This is called a balanced chromosomal translocation. People with a chromosomal translocation usually have no physical signs or symptoms, but when germ cells (eggs or sperm cells) are formed, some of them have abnormal chromosomes. If an embryo is formed from such germ cells, a chromosomal disorder occurs.

However, quite often during the formation of germ cells, chromosomes are distributed incorrectly, and the cell may contain not 23 chromosomes, but, for example, 24.

During fertilization, when the egg and sperm fuse together, the two sets of chromosomes are combined. If an egg or sperm cell carries the wrong number of chromosomes, the chromosome set of the embryo will also be abnormal.

Depending on how much the chromosomal set differs from normal, three outcomes are possible:

1. The embryo stops developing before pregnancy occurs. Pregnancy does not occur.

2. The pregnancy occurs, but the embryo develops abnormally. This leads to pregnancy loss.

3. A child is born with a chromosomal syndrome - a severe incurable disease, such as Down syndrome, Edwards syndrome or Patau syndrome.

About half of the cases of pregnancy loss in the first trimester are caused by a chromosomal abnormality. Therefore, the test is most relevant for early pregnancy loss. In later pregnancy, chromosomal abnormalities usually result in multiple malformations. If there are no malformations, it is unlikely that the test will reveal a chromosomal abnormality. Therefore, the test is more informative when the obstetrician-gynecologist suspects chromosomal abnormalities in the fetus.

The test will help you understand the cause of pregnancy loss,which will increase your chances of preventing a loss next time. The results of the test should be discussed with your doctor. The test will be most relevant in specific cases:

1. Termination of pregnancy for medical reasons when multiple fetal malformations are detected;
2. Repeated pregnancy loss, especially if no testing was done after the previous occurrence.

During the testing process, we select fetal tissue fragments from the aborted material. We wash them from the maternal cells and isolate a DNA sample, which we prepare for sequencing. We then examine the sample using NGS technology. The whole genome is read; that is, the test affects the entire chromosome, not just parts of it. Thanks to this technology, we can see if any chromosome or its fragment is too small or too large.

We look for chromosomal abnormalities in the sequencing results. If there are segmental abnormalities (changes in the number of copies of a fragment of a chromosome rather than a whole chromosome), we evaluate such an occurance in terms of its significance for the course of the pregnancy. We only include in the test report significant occurrences that may have influenced the non-developement of the pregnancy.

To search for chromosomal abnormalities, it is important to examine fetal DNA. But in the aborted material it can mix with the mother's DNA, and this distorts the result. If we have doubts about the purity of a sample of fetal DNA, we do additional testing and see if there is an admixture of maternal DNA. During the test, we compare the DNA in the sample to DNA from the mother's blood. You can read more about the testing technology in the Paternity sections "How it works" tab.

If the DNA of the embryo and the mother are mixed, we take a new batch of embryonic tissue and repeat the test all over again. In some cases (about 5% of samples), the biological material received by the laboratory does not contain embryonic tissue, but only maternal one. In this case, the analysis cannot be performed, and the laboratory will refund the money.  

As a result of the test you will receive data on the chromosome set in the embryo cells: whether it is normal, and if not — how exactly it differs from the norm.

For correct interpretation of the result and understanding of further actions we recommend consult with a geneticist.

The doctor will conclude whether the pregnancy loss was an accidental event and tell you about the individual risks of repeated pregnancy loss. In some cases, the doctor may recommend karyotyping of the couple. This test determines the number and structure of chromosomes. Karyotyping may reveal balanced chromosomal translocation in either parent, a possible cause of repeated miscarriages.

If a chromosomal translocation is detected, the geneticist may suggest in vitro fertilization (IVF) with special genetic testing — preimplantation genetic testing for aneuploidy (PGT-A). This method allows an embryo with a normal number of chromosomes to be selected for transfer into the uterus.

The Light in Hands Charitable Foundation supports anyone who has faced difficulties on the path to parenthood.

Typically, pregnancy loss is a one-time event.

Most women who experience it go on to have healthy pregnancies and births in the future. Less than 5 percent of women experience two consecutive pregnancy losses, and only 1 percent experience three or more. If you experience two or more consecutive losses, it is advisable to find the cause of these occurrences. But even if no cause is identified, don't give up hope. Between 60 and 80% of women with unexplained recurrent pregnancy loss will end up carrying a healthy pregnancy.

There are many reasons why a pregnancy stops developing.

And it is not always possible to establish the exact reason for the loss. Most pregnancy losses are not due to something the woman did wrong. And unfortunately, most pregnancy losses cannot be prevented. Hard labor, exercise, being sexually active, or taking oral contraceptives before pregnancy does not cause miscarriages. Early toxicosis also does not affect the success of the pregnancy. Some women who experience early pregnancy loss think it is due to a recent fall, anxiety, or stress. This is not the case in most situations.

2. Certain health conditions in women

These include uncontrolled diabetes, infectious diseases, hormonal issues, peculiarities of the uterine structure, thyroid diseases, antiphospholipid syndrome.

3. Use of certain medications

The use of certain medications, as well as smoking more than 10 cigarettes a day and drinking alcohol in moderate doses may be associated with pregnancy loss. During pregnancy, it is better to avoid smoking and drinking alcohol, not to exceed caffeine intake of more than 100 mg per day (4-5 cups of coffee). Before taking any medication, it is recommended to carefully inspect the instructions regarding the use of the drug during pregnancy. If possible, it is recommended to avoid exposure to occupational hazards.