A chorionic villus biopsy is a prenatal test that is performed during pregnancy to detect possible abnormalities in the fetus. You can go through it if the received information helps you make an important decision about the future of your baby. Read on to find more about pregnancy test CVS.
Pregnancy Test CVS: What You Need to Know
It is carried out in the first trimester of pregnancy. If the doctor diagnoses a serious abnormality, you will have time to prepare for the birth of a child with a pathology or make a decision to terminate the pregnancy. If the result is negative, this will allow you to worry less.
Using pregnancy test CVS, you can determine the presence of many diseases and defects, including Down syndrome. However, remember that the answer you receive is not always absolutely correct. No test will give you a 100% guarantee that your baby will be born completely healthy.
A chorionic villus biopsy does not reveal a neural tube defect, for example, a congenital spinal hernia. If you have fears of developing such a disease, then you can undergo amniocentesis instead of this test. Or, after a chorionic villus biopsy, an additional blood test is performed to determine the problem.
Pregnancy test CVS does not apply to normal safe procedures, as it carries the risk (small) of a miscarriage. For example, 1-4 women out of 400 who performed this test may have a miscarriage. You have the right to decide whether the received information is worth the life of your unborn child.
What’s more, such a procedure is quite expensive. Many insurance companies cover these costs for women over 35. If you do not belong to this category and the price is unacceptable for you, you can always choose an alternative test.
Chorionic villus biopsy – what is it?
This is a test that allows you to identify abnormalities in the development of the fetus. It is usually carried out at the end of the first trimester, between the 10th and 12th weeks of pregnancy.
A chorionic villus biopsy helps diagnose:
- Congenital malformations associated with chromosomal abnormalities, for example, Down syndrome.
- Many hereditary diseases, such as early childhood amavrotic idiocy and hemophilia.
- Since this test does not detect a neural tube defect (for example, a congenital spinal hernia), it is recommended to additionally do a blood test for alpha-fetoprotein. The latter is carried out at 16-18 weeks of pregnancy.
Why Should One Pass Pregnancy Test CVS?
You should undergo such a procedure if:
- A screening test conducted in the first trimester found that the fetus is likely to develop Down syndrome (This is an ultrasound of the fetal neck (for transparency of the cervical fold) and a maternal blood test).
- You are over 35 years old. This age of the mother increases the risk of developing Down syndrome in the child. The older the woman, the greater the likelihood of a baby having such an anomaly. In 1 case out of 350 in a pregnant woman over 35 years old a child is born with the aforementioned defect. If the mother is 40 – 1 out of 100 children is at risk of being born with Down syndrome. Parents (together or only one) can be carriers of a hereditary family disease (genetic disorder), for example, early childhood amavrotic idiocy, sickle cell disease or abnormalities in the development of chromosomes, which can be passed on to the child.
- You may have medical reasons for determining the sex of the unborn baby. This need is most often due to the fact that one of the parents is a carrier of a disease that causes abnormalities in the development of a certain gender, for example, Duchenne muscular dystrophy or hemophilia. Both of these diseases are found mainly in men.
- You already have a child with Down Syndrome or another chromosomal defect.
- Ultrasound showed that the fetus is predisposed to the development of congenital malformation.
Chorionic Villus Biopsy – How to Conduct this Test?
To conduct such a test, a sample of chorionic villus cells is taken and examined for defects. Chorionic villi are small finger-shaped outgrowths that are located in the placenta. The genetic material of these villi is identical to that of the fetus.
A doctor can take a sample in two ways:
- Holds a foldable tube (probe) through the vagina and cervix to the placenta (transcervical biopsy of the chorionic villi).
- A thin long needle passes through the abdominal cavity and enters the placenta (abdominal biopsy of the chorionic villi). This procedure resembles a puncture of the fetal bladder.
Ultrasound is used to direct the probe or needle into the desired part of the body.
The Results of Pregnancy Test CVS
A negative pregnancy test CVS result will confirm that the fetus has no developmental abnormalities at the chromosomal or gene level. This is certainly a good indicator. However, keep in mind that there are no procedures that can 100% exclude the occurrence of health problems or guarantee that the baby will be born completely healthy.
If it is confirmed that the fetus is developing a serious illness, you will have time to think everything over and decide how to proceed. In some cases, it depends on various factors, for example, on the type of the defect or your personal reaction. Depending on this, you may have the following thoughts:
- Should I keep my pregnancy? If a fetus is found to have a serious defect, some women decide to terminate their pregnancy (medical abortion) during the first trimester. Others just need time to prepare themselves and their loved ones for the birth of a baby with certain health troubles.
- Where is it better to give birth? If a fetus is found to have a defect that requires surgical intervention during or after delivery, the best option would be to give birth in a specialized clinic where they provide this type of service.
Chorionic Villus Biopsy – Possible Risk during the Test
This procedure increases the risk of:
- Infections in the uterus.
- Miscarriage. Some studies have shown that during the procedure, the risk of spontaneous abortion is 1 in 400 cases. Others speak of a higher risk (2 – 4 out of 400 cases). The likelihood of this kind of consequences increases if the test is conducted by an insufficiently qualified doctor.
- This test virtually eliminates the possibility of mixing the blood of the mother and the fetus. If you have a negative Rh factor, you will be given a vaccine before the procedure to avoid Rh sensitization.
What Happens If You Ignore the Prescribed Procedure?
If you do not undergo a chorionic villus biopsy or other prenatal diagnostic check, you run the risk of having a baby with one of the congenital malformations that you didn’t even know about or with Down syndrome, etc. The risk is the following:
- The birth of a child gets in this case to a risk group, since the doctor does not know about possible congenital pathologies.
- You can give birth in a hospital where there is no neonatal intensive care unit for sick and premature babies.
- Most parents are not mentally prepared for the birth of a child with a serious illness or a birth defect.
- Consult your healthcare provider for all necessary tests. With the help of additional tests, it is also possible to detect the presence of a genetic disease.
Reasons for Performing Pregnancy CVS Test
- At the time of conception, you will turn 35 years old or more. You are concerned about the increased risk of possible genetic abnormalities in the fetus.
- You think that it is more important to know about abnormalities in the development of the fetus than to constantly worry about a possible miscarriage.
- There have been cases of birth defects in your or your partner’s family that a chorionic villus sampling can detect.
- You or your partner are carriers of a hereditary disease or chromosomal defect that the child may inherit.
- You want to find out as early as possible whether there are abnormalities in the development of the fetus, so that with a positive result you have time to make a decision: to terminate the pregnancy or mentally prepare for the birth of a child with a health defect.
Perhaps you know additional reasons why you need to undergo a chorionic villus biopsy.
Reasons Not to Pass Pregnancy Test CVS
- You are under 35 years old. And you have no reason to worry about risk factors for Down syndrome or another genetic disease.
- You are more worried about a possible miscarriage after the test than about the result of a procedure that can reveal abnormalities in the development of the fetus.
- You agree to wait and undergo amniocentesis at a later stage of pregnancy.
- Also, you are concerned that this test does not detect all possible developmental abnormalities. For example, it will not detect a neural tube defect.
- A positive chorionic villus biopsy will not affect your pregnancy decision.
Perhaps you know additional reasons why you don’t need to undergo a chorionic villus biopsy.