Although it can be performed earlier, this may increase the risk of complications of amniocentesis and is usually avoided. During the test, a long, thin needle is inserted through your abdominal wall, guided by an ultrasound image.
The needle is passed into the amniotic sac that surrounds the foetus and a small sample of amniotic fluid is removed for analysis. The test itself usually takes about 10 minutes, although the whole consultation may take about 30 minutes. Amniocentesis is usually described as being uncomfortable rather than painful.
Some women describe experiencing a pain similar to period pain or feeling pressure when the needle is taken out. Read more about what happens during amniocentesis. The first results of the test should be available within three working days and this will tell you whether your baby has a health condition or chromosomal condition. If rarer conditions are also being tested for, it can take two to three weeks or more for the results to come back.
If your test shows that your baby has a health condition or chromosomal condition, the implications will be fully discussed with you. You may choose to continue with your pregnancy, while gathering information about the condition so you're fully prepared, or you may consider ending your pregnancy abortion. Read more about the results of amniocentesis. Before you decide to have amniocentesis, the risks and possible complications will be discussed with you. One of the main risks associated with amniocentesis is miscarriage.
Around 1 in every 0. There are also some other risks, such as infection or needing to have the procedure again because it wasn't possible to accurately test the first sample that was removed. The risk of amniocentesis causing complications is higher if it's carried out before the 15th week of pregnancy, which is why the test is only carried out after this point. Read more about the possible complications of amniocentesis. An alternative to amniocentesis is a test called chorionic villus sampling CVS.
This is where a small sample of cells from the placenta the organ that links the mother's blood supply with her unborn baby's are removed for testing. It's usually carried out between the 11th and 14th weeks of pregnancy, although it can be performed later than this if necessary.
The risk may be higher in twin pregnancies. If you're offered tests to look for a health condition in your baby, a specialist involved in carrying out the test will be able to discuss the different options with you, and help you make a decision.
Amniocentesis is offered to pregnant women at risk of having a baby with a health condition or chromosomal condition. It will diagnose any health condition or chromosomal condition at an early stage. Amniocentesis isn't routinely offered to all women during pregnancy.
It's offered if your test results or medical or family history suggest you have an increased chance of having a baby with a health condition or chromosomal condition. Amniocentesis can be used to diagnose a number of health conditions and chromosomal conditions including:.
Amniocentesis can also test for neural tube defects. The most common neural tube defect is spina bifida, which can cause learning difficulties and paralysis weakness of the lower limbs. If you're offered CVS, ask your doctor or midwife what the procedure involves and what the risks and benefits are before deciding whether to have it. ARC is a charity that offers information, advice and support on all issues related to screening during pregnancy.
The test will usually tell you whether your baby will be born with any of the health conditions or chromosomal conditions that were tested for. A result showing that a health condition or chromosomal condition was detected will give you plenty of time to decide how you want to proceed with your pregnancy. Read about the results of amniocentesis for more information. You may feel this risk outweighs the potential benefits of the test. Read more about the risks of amniocentesis. Amniocentesis involves taking a small sample of amniotic fluid so the cells it contains can be tested.
Amniotic fluid surrounds the fetus unborn baby in the womb uterus. You won't usually need to do anything special to prepare for amniocentesis. You can eat and drink as normal beforehand. In some cases, you may be advised to avoid going to the toilet for a few hours before the test, because it's sometimes easier to perform when your bladder is full. Your doctor or midwife will tell you about this before you attend your appointment. You'll have an ultrasound scan before and during amniocentesis.
An ultrasound scan uses high-frequency sound waves to produce an image of your womb that's relayed to a monitor. Before the needle is inserted into your abdomen, the area may be numbed with anaesthetic. This involves having a small injection into your belly that may sting slightly.
However, anaesthetic isn't usually necessary because research suggests that it doesn't have much effect in most cases. An antiseptic solution will first be used to clean your abdomen to minimise the risk of infection. A long, thin needle is then inserted through your abdominal wall.
Sometimes, the medicine is given through a shot in the skin on the belly area. The skin is cleaned with a disinfecting liquid. Your provider inserts a long, thin needle through your belly and into your womb. A small amount of fluid about 4 teaspoons or 20 milliliters is removed from the sac surrounding the baby. In most cases, the baby is watched by ultrasound during the procedure. Results of genetic testing usually take about 2 weeks. Other test results come back in 1 to 3 days. Before the test, blood may be taken to find out your blood type and Rh factor.
Amniocentesis is usually offered to women who are at increased risk of having a child with birth defects. This includes women who:. Amniocentesis can be used to diagnose many different gene and chromosome problems in the baby, including:.
Note: Amniocentesis typically is the most accurate test for genetic conditions and malformation, Although rare, a baby may still have genetic or other types of birth defects, even if amniocentesis results are normal. Genetic screening and prenatal genetic diagnosis.
Obstetrics: Normal and Problem Pregnancies. Philadelphia, PA: Elsevier; chap In: Fowler GC, eds. Pfenninger and Fowler's Procedures for Primary Care. Wapner RJ, Dugoff L. Prenatal diagnosis of congenital disorders. Reviewed by: John D. In this instance, the implications will be fully discussed with you and you'll need to decide what to do next. If the test finds that your baby will be born with a condition, you can speak to a number of specialists about what this means.
These could include a midwife, a doctor who specialises in childrens' health consultant paediatrician , a geneticist and a genetic counsellor. They'll be able to give you detailed information about the condition to help you decide what to do, including the possible symptoms your child may have, the treatment and support they might need, and whether their life expectancy will be affected.
A baby born with 1 of these conditions will always have the condition, so you'll need to consider your options carefully. As well as discussing it with specialist healthcare professionals, it can help to talk things over with your partner and speak to close friends and family. Page last reviewed: 17 April Next review due: 17 April
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