When is amniocentesis done?

From 15+0 weeks onwards. RCOG grades this a strong recommendation — amniocentesis should not be performed before 15+0 weeks, because earlier procedures have been associated with higher complication rates including talipes. Before 15 weeks there is less amniotic fluid available and early amniocentesis has been associated with higher complication rates, which is why it is not generally performed earlier. If you need an answer sooner, CVS is the alternative and can be done from around 11 weeks. There is no strict upper limit — amniocentesis can be performed later in pregnancy where there is a reason, such as an abnormality found at the anomaly scan. Timing considerations worth thinking about: Results take time, so factor that in when planning. If your decision-making might depend on the result, discuss the relevant gestational limits with your obstetrician early. In India the Medical Termination of Pregnancy Act governs this, and your obstetrician will explain what applies. If your NIPT was high-risk, do not delay the conversation about confirmatory testing. Repeated deliberation can consume the window without a decision being made. If you are Rh negative, you will need anti-D after the procedure. Ask your unit how quickly they can arrange the procedure, and how quickly results come back for your specific test — a chromosome analysis and a microarray have different turnaround times.