Menu Invasive Tests Chorion Villus Sampling Amniocentesis Amniocentesis What is amniocentesis? Amniocentesis involves the examination of cells in the fluid from around the fetus (amniotic fluid). The cells in the amniotic fluid originate from the baby and so the chromosomes present in these cells are the same as those of the baby. How is amniocentesis done? Amniocentesis involves passing a thin needle into the uterus in order to remove a small volume of amniotic fluid. The needle is carefully observed using ultrasound scan. The fluid is fetal urine and the amount removed by amniocentesis reaccumulates within a few hours. The procedure lasts 1 minute and afterwards we check that the fetal heart beat is normal. What should I expect after amniocentesis? For the first couple of days you may experience some abdominal discomfort or period-like pain. You may find it helpful to take simple painkillers like paracetamol. If there is a lot of pain, bleeding, loss of fluid from your vagina or if you develop a temperature please seek medical advice. When can I expect to get the results? The results for Down’s syndrome and other major chromosomal defects are usually available within 3 days. The results for rare defects take 2 weeks. As soon as we get the results, we will call you to let you know What are the risks associated with amniocentesis? The risk of miscarriage due to amniocentesis is about 1% and this is the same as the risk from chorion villus sampling. If you were to miscarry due to the test, this would happen within the next five days. Some studies have shown that when amniocentesis is performed before 16 weeks there is a small risk of the baby developing club feet. To avoid this risk we never perform amniocentesis before 16 weeks. Book Now Address The Fetal Medicine Centre 137 Harley Street London, W1G 6BG United Kingdom Tel: +44 (0)20 7486 0476 Fax: +44 (0)20 7486 0294 Email: enquiries@fetalmedicine.com Opening times Monday to Friday 9.00 am to 6.00 pm Saturday 9.00 am to 5.00 pm Contact Us The Fetal Medicine Centre is aware of the General Data Protection Regulation and changes to data protection legislation. This is one of a number of legislative requirements that we must adhere to and as part of the service that you receive from us these requirements are built into our systems and processes. The Fetal Medicine Centre actively supports the aims of the Fetal Medicine Foundation (FMF) in terms of its research objectives. Anonymised data that we obtain will routinely be provided to the FMF for research purposes. If you have any concerns about this please contact us and we can help explain the options that are available to you. © 2021 The Fetal Medicine Centre.