Amniocentesis is a form of prenatal examination. This means an examination that is done during pregnancy to detect abnormalities in the unborn child. In this process, amniotic fluid is drawn from the uterus through the abdomen with a needle.
The amniotic fluid contains cells of the unborn child. These cells provide information about:
- presence of chromosome abnormalities. The chromosomes contain the hereditary characteristics of the child
- the content of the protein alpha-fetoprotein (AFP) in the amniotic fluid. An increase in this protein may indicate an open spine or lack of brain (cat’s head) in the child. These abnormalities are also called neural tube defects
An amniocentesis prenatal examination can be performed at a gestational age of about sixteen weeks.
Why is an amniocentesis done as a prenatal examination?
There are various reasons for choosing an amniocentesis prenatal examination, for example, because of your age or the fact that you have previously had a child with a serious congenital defect.
Not a good reason for amniocentesis is to want to be reassured that everything is fine with your child and that it has no birth defects.
Amniocentesis cannot show all abnormalities. Amniocentesis is also not completely without danger. Even if the result of the amniocentesis shows no abnormalities, your child may still be born with a congenital abnormality.
Before having an amniocentesis, it is important to consider what to do if your child is diagnosed with an abnormality. You will then be faced with the difficult and radical choice whether or not to terminate the pregnancy. If you are sure in advance that you do not want to terminate the pregnancy, you should consider carefully whether you want to have an amniocentesis.
See also, Unwanted pregnancy
When is amniocentesis done?
In some countries, it has been agreed that pregnant women with an increased risk of chromosome abnormalities are eligible for an amniocentesis. You are eligible for an amniocentesis prenatal examination if:
- you are 36 years or older when you are eighteen weeks pregnant – from 1 January 2015 these women will no longer be eligible for reimbursement.
- you or your partner have previously given birth to a child with a chromosome abnormality
- you or your partner is a carrier of a chromosome abnormality or another hereditary condition
- ultrasound examination found indications of abnormalities in your unborn child
- you or your partner have previously had a child with an open back or without a skull cap
- if you have had a positive triple test or an ultrasound examination has seen a thickened neck fold in your child
- you or your partner was born with an open back
- you are taking medicines during pregnancy that increase the risk of spina bifida in your child
- you have diabetes for which you were already taking insulin before pregnancy, which also increases your child’s risk of spina bifida
In these situations, the costs of the amniocentesis prenatal examination will be reimbursed. If you qualify for additional testing, the general practitioner, midwife, or gynecologist will discuss the various options with you in detail.
See also, If getting pregnant doesn’t work
Types of prenatal examination:
- NIPT (Non-Invasive Prenatal Test)
- triple test
- flake test
- nuchal fold measurement, possibly with blood tests
If you want an amniocentesis prenatal examination, you will be referred to a hospital where this test can be performed. In some hospitals there is first a discussion about the research; in other hospitals, the examination is carried out immediately.
Make clear agreements about what will be determined and whether you want to be informed about unexpected, additional findings. The sex of the child is always determined, please indicate clearly whether you want to know.
how is an amniocentesis performed?
An amniocentesis is usually performed at a gestational age of 16 weeks. The puncture is performed on an outpatient basis by the gynecologist in the hospital. First, the skin of your abdomen is disinfected with alcohol or iodine. Subsequently, an ultrasound determines the location of the injection. A thin needle is then used to pierce the stomach wall. This stinging is equally painful.
The ultrasound checks whether the needle is going to the right place. Then two tubes (20 ml) of amniotic fluid are taken. If insufficient amniotic fluid is obtained, the puncture may need to be repeated. The procedure takes about ten to fifteen minutes.
Your child will not be bothered by the amniocentesis prenatal examination. At a pregnancy of sixteen weeks, the amount of amniotic fluid in the uterus is approximately 200 ml. The quantity purchased was replenished within a few hours. If your blood rhesus is negative, you will receive an anti-D injection afterward.
Post amniocentesis instructions
After the amniocentesis prenatal examination, you can go home. Some women experience some pulling or cramping pain in the abdomen or at the site of the injection for up to one or two days after the puncture. That is normal. After two days these complaints should be over. It is good to slow down these days.
The collected amniotic fluid is sent to the laboratory. There, the cells from the amniotic fluid, which come from your child’s skin and mucous membranes, are cultured and examined for abnormalities on the chromosomes. This takes time, the result of the puncture is usually known after about two weeks. The result of the AFP level is known earlier, usually after a week.
What information can an amniocentesis give you?
The following abnormalities can be detected with an amniocentesis:
- chromosome abnormalities such as Down’s syndrome
- metabolic diseases
- DNA abnormalities
- amount of the substance alpha-fetoprotein (AFP)
Alfafoetoprotein (AFP) is a protein of the unborn child that can end up in the amniotic fluid in certain abnormalities. An increased amount of this may indicate the presence of an open spine (spina bifida) or the absence of the skullcap and part of the brain. In nine out of ten cases, these deviations can be demonstrated. Sometimes there is still a firm membrane over the open spine so that the AFP does not end up in the amniotic fluid. In that case, the amniocentesis prenatal examination cannot detect the spina bifida.
What information cannot an amniocentesis give you?
With an amniocentesis, abnormalities on the chromosomes can be detected. Chromosomes are coiled structures of chains of DNA, the code of the genetic material. A small abnormality in the DNA can cause a birth defect in your child, without this being visible on the chromosomes.
Even if the amniocentesis shows no abnormalities on the chromosomes, your child may still have a congenital abnormality. In the Netherlands, one in twenty children has a congenital abnormality, but all these abnormalities are not nearly as serious.
What does the result of an amniocentesis mean?
The results of the amniocentesis prenatal examination will be known after two to three weeks. This is an exciting and long-term period for most pregnant women and their partners. What will the result mean for you and your unborn child? You may find it difficult to enjoy the pregnancy, even though you are clearly pregnant anyway and can sometimes feel the baby move.
What can you do if the result shows no abnormalities?
If the result of the amniocentesis shows no abnormalities in the unborn child, most parents are relieved. From that moment on they have the feeling that they are really pregnant. Nevertheless, a good result does not mean that your child will certainly not have any abnormalities.
One in twenty children is born with a congenital defect; by no means all these deviations are equally serious. Amniocentesis can only show abnormalities of the chromosomes and indications of abnormalities in the construction of the nervous system.
What can you do if the result does show an abnormality?
When an abnormality is detected via amniocentesis prenatal examination, it is a big shock. All kinds of feelings can play a role: bewilderment, disbelief, anger, feelings of guilt, not wanting to know the result.
As parents, you now have to make a difficult decision about what to do with the pregnancy. Only you and your partner can assess what this result means for you and your unborn child and whether you have the options together to raise a child with these abnormalities, or whether you choose to terminate the pregnancy.
Care providers often think that you want to terminate the pregnancy if you have heard that you are expecting a child with an abnormality. But this is certainly not necessary and is entirely your own choice. Take the time to think carefully about this.
Ask your gynecologist, general practitioner or midwife for information. The clinical geneticist or a parent organization can also give you information about what it means to have a child with the found abnormality. They also know social workers or psychologists who have a lot of experience in counseling parents who have been in a similar situation.
List all arguments for and against. Ultimately, you and your partner are the ones to make the best choice in this situation, no one else can determine that for you.
1. Continuing the pregnancy
You and your partner can choose to continue the pregnancy. Some parents like that they can prepare for the arrival of a child with an abnormality. They will look for information about it and will probably arrange things that may be necessary. Information can be obtained from parent and patient associations or from clinical genetic centers.
Even if the amniocentesis has shown that you will have a child with an abnormality, the amniocentesis prenatal examination will never be able to indicate to what extent your child will be affected by the abnormality.
For example, there is a big difference in functioning between different children with Down syndrome. There are increasingly better treatment methods to treat additional problems in Down syndrome, such as heart problems.
See also, Pregnancy and medicine use
2. Terminating the pregnancy
The other option, after the results of the amniocentesis prenatal examination, indicates that your unborn baby has an abnormality, is to terminate the pregnancy. This is also a difficult and far-reaching decision.
Because the result of the amniocentesis has lasted at least two to three weeks, you are now eighteen to nineteen weeks pregnant. You often already have a pregnancy belly or have already felt the baby move.
It is possible to terminate the pregnancy up to a gestational age of 24 weeks. The pregnancy is terminated by inducing the delivery in the hospital. You will receive medicines that induce contractions through an IV. For example, the delivery will start within 24 to 48 hours and your baby will be born.
There is a chance that the placenta will not be born spontaneously. If so, it should be removed under anesthesia.
See also, Everything about abdominal surgery
Because your child is not yet viable, it will usually die before, during, but sometimes also after delivery. After the delivery, you can keep your baby with you and you can say goodbye to your child in any way you want. Many people take pictures of their baby as a reminder.
After inducing the delivery and the loss of their child, parents go through a very difficult time. All kinds of feelings come up. Why did we have a child with a birth defect? What have we done wrong? Were we allowed to decide about the life of our child? These feelings are very normal.
Take time to come to terms with the loss of your child. You may need months, sometimes more than a year, to make sense of the loss and to feel like participating in society again. Professional guidance can often help with this.
Are there any amniocentesis risks?
As a result of the amniocentesis prenatal examination, there is a very small chance that the pregnancy will end in a miscarriage. Fortunately, this rarely happens: one in 300 pregnancies ends in a miscarriage after an amniocentesis.
NIPT (Non-Invasive Prenatal Test) is an alternative to amniocentesis, which avoids the higher risk of miscarriage. This test is partly reimbursed through a subsidy scheme.
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