Amniocentesis is a fairly common and safe procedure. For most women, the benefits of having amniocentesis – in terms of diagnosing problems with the developing baby – significantly outweigh the risks.
However, in order to make an informed decision, it is important to be aware of the possible complications during or after amniocentesis. These are outlined below.
Injury from the needle
During amniocentesis, the placenta (the organ that links a pregnant woman's blood supply to her unborn baby's) may be punctured by the needle. Sometimes this is necessary to access the amniotic fluid. If this happens, the puncture wound usually heals without any more problems developing.
Ultrasound (where high frequency sound waves are used to create images) is now commonly used to guide the needle. This significantly reduces the risk of injury.
Infection
In very rare cases, an infection may develop if the procedure introduces bacteria to your amniotic sac (the sac surrounding the foetus that contains amniotic fluid). This can cause:
- a high temperature (fever) of 38ºC (100.4ºF) or above
- tenderness of your abdomen (tummy)
- contractions (when your abdomen tightens then relaxes)
You should seek medical attention if you have any of these symptoms. The risk of developing a serious infection from amniocentesis is estimated to be less than 1 in 1,000.
Rhesus disease
Rhesus disease is a condition where proteins in a pregnant woman’s blood attack her baby's blood cells.
Rhesus disease is only possible if your blood is rhesus-negative and your baby's blood is rhesus-positive. If this is the case, amniocentesis could trigger rhesus disease if your blood is exposed to your baby’s blood during the procedure.
In this situation, you will be given an injection of anti-D immunoglobulin after having amniocentesis. Immunoglobulin is a solution of antibodies (proteins produced by the body to fight disease-carrying organisms) that can prevent rhesus disease from occurring.
See the Health A-Z topic about Rhesus disease for more information about this condition and how it is prevented.
Club foot
Amniocentesis may cause club foot in your baby. This is when the baby is born with a deformed ankle and foot. However, the likelihood of this happening is higher if you have amniocentesis before week 15 of your pregnancy.
See the Health A-Z topic about Club foot for more information about this condition.
Miscarriage
There is a small risk that amniocentesis can cause a miscarriage (the loss of the pregnancy). The risk is estimated to be around 1 in 100.
See the Health A-Z topic about Miscarriage for more information about coping with the loss of your baby.
Inconclusive results
Following the amniocentesis procedure, it can be reassuring if the results indicate that your foetus has normal chromosomes (the parts of the body’s cells that carry genes), and that there are no signs of any developmental problems.
However, be aware that amniocentesis cannot test for every condition or disease, and it cannot guarantee that your baby will be born completely healthy. See Amniocentesis - results for more information.
