The book elucidates a practical method for prenatal screening and detecting Down syndrome in a simple and easy-to-understand language. It provides thorough knowledge on the subject, and each chapter covers a specific topic, making this book an essential quick-reference guide for every antenatal clinic. The book contains chapters on maternal serum screening, noninvasive prenatal testing (NIPT), invasive testing with amniocentesis and CVS, and screening in twins. It also includes advanced chapters on multi-step screening protocols, uncommon aneuploidies, screening for preeclampsia, and open neural tube defects for clinicians interested in fetal medicine. Down syndrome is the most typical genetic condition affecting over 5 million individuals globally. Rapid advances in the medical field make it possible to identify most of these babies before birth. Hence, aneuploidy screening is now offered to pregnant women worldwide. The book aims to helpobstetricians and gynecologists diagnose Down syndrome and other aneuploidies in pregnancy, avoid unnecessary testing, and remain safely within medico-legal boundaries. It is also helpful for fetal medicine students. The book helps the readers address challenging clinical scenarios and confusing test results.