When do I need an amniocentesis? 1. Mothers-to-be who are over 35 years old at the time of their expected delivery. 2.Mothers-to-be with high or critical risk of Down’s syndrome screening. 3.Mothers-to-be who have given birth to a child with congenital defects, especially a child with chromosomal abnormalities. 4.One of the spouses is a carrier of chromosomal abnormalities or balanced ectopic. 5.Thalassemia both partners are homozygous carriers. 6.Family history of hemophilia, DMD or other genetic diseases 7.Exposure to substances that may cause fetal congenital defects during pregnancy 8.Mothers-to-be who need to be matched for a child with β-thalassemia What is the most appropriate time to do amniocentesis? The best time to perform prenatal diagnosis is between 18 and 24 weeks of gestation. Because the fetus is small and the amniotic fluid is relatively large at this time, the fetus floats in the amniotic fluid and is surrounded by more amniotic fluid, so when the amniotic fluid is extracted by needle puncture, it is not easy to stab the fetus, and the extraction of 20 ml of amniotic fluid only accounts for 1/20 of the total amniotic fluid, which will not cause abortion due to sudden decrease of pressure in the uterine cavity. It can be used for karyotype analysis and diagnosis of chromosomal genetic diseases, and also for diagnosis of genetic diseases and metabolic diseases using amniotic fluid cell DNA. Does amniocentesis have any effect on the baby? Amniocentesis is performed under the guidance of ultrasound, so the baby will not be punctured. The amount of amniotic fluid extracted in the middle of pregnancy is only 5-8% of the total amniotic fluid, and it will be replenished soon, so there is no need to worry about affecting the fetal development. Does amniocentesis hurt? Do I need anesthesia? The needle used for amniocentesis is very thin, thinner than the needle used for blood sampling and anesthesia, and it does not feel very painful, similar to blood sampling. What should I pay attention to after amniocentesis? 1. If you have any history of allergies, special diseases or other conditions that need to be explained, please inform the doctor during the pre-operative registration. 2.No intercourse three days before the operation; please take a bath one day before the operation; please urinate 10 minutes before the operation. 3.If you have a cold, fever, skin infection or other abnormalities 3 to 7 days before surgery, please inform the doctor at the time of pre-operative registration. 4.For life care, please arrive at the hospital one hour early after lunch to rest and wait, and please have a family member accompany you. 5.After the operation, at least half an hour of meditation and rest before going home by car. If you do not live in the city, it is recommended to stay locally for one night before going home. 6.No bathing within 24 hours after surgery, pay more attention to rest, avoid a lot of exercise, and physical labor such as carrying heavy objects. 7.No intercourse for one month after surgery. 8.If you have abdominal pain, abdominal distension, vaginal water, bleeding, fever and other symptoms seven days after surgery, please go to the obstetrics and gynecology department of the hospital immediately. 9.Please go to our hospital or local hospital for maternity checkup seven days after the operation. How long does it take to get the report of amniocentesis? It takes 3 weeks for the karyotype report of amniocentesis. We have a rapid aneuploidy chromosome test, which can quickly exclude the 13th, 18th, 21st and sex chromosome number abnormalities, and we can get the report within a week. We will notify you by text message and phone call, so please make sure your cell phone is open and that you have left the correct number after the puncture. Why does the karyotype report take so long? The chromosome karyotype is different from normal laboratory tests because the cells have to be cultured, which requires inoculation, culturing, fluid exchange, harvesting, production, and reading, so it takes longer. If the amniotic fluid chromosome report is normal, does it mean that there is nothing wrong with my baby? Although karyotype is the gold standard for chromosome testing, a normal karyotype does not guarantee that there is nothing wrong with your fetus. A fetal structural abnormality does not necessarily mean that there is a chromosomal abnormality, and a normal karyotype does not necessarily mean that the child does not have structural or functional abnormalities. Moreover, the resolution of karyotype is limited and only deletions or duplications greater than 5Mb can be identified. Mothers-to-be with normal fetal chromosomes must go to regular hospitals for regular fetal ultrasound examinations to rule out fetal structural abnormalities. What other items can amniocentesis check besides chromosomes? Amniocentesis is a method of obtaining fetal samples. In addition to checking chromosomes, amniotic fluid can also be used to check for thalassemia genes, as well as genes for hemophilia, DMD, polycystic kidney and other genes according to different needs, and also for paternity testing. For mothers with suspected fetal structural abnormalities or multiple fetal soft indicators, fetal growth restriction, children with mental retardation, cerebral palsy, or mental retardation, we recommend a fetal microarray in addition to the traditional cytogenetic examination during amniocentesis. It can detect microdeletions and duplications of chromosomes, diagnose fetal abnormalities more accurately and assess the prognosis without the need for repeat punctures, and requires only 10 ml of amniotic fluid, which has no effect on the fetus.