PFSI010 ››› Weeks 1–4 Weeks 5–8 Weeks 9–12 Weeks 13–16 Weeks 17–20 Weeks 21–24 • Timing: 10–13 weeks • Blood test plus NT ultrasound exam • Screens for Down • syndrome and trisomy 18 First-trimester screening Second-trimester screening (“quad screen”) • Timing: 15–22 weeks • Blood test • Screens for Down syndrome, trisomy 13, trisomy 18, and NTDs Standard ultrasound exam • Timing: 18–22 weeks • Screens for some physical defects Integrated screening and sequential screening • Timing: 10–22 weeks • Combines first-trimester and second-trimester screening test results in various ways • Screens for Down syndrome, trisomy 13, trisomy 18, and NTDs Diagnostic Tests Screening Tests CVS • Timing: 10–13 weeks • Tests fetal cells in a - sample of chorionic villi • Detects Down syndrome, trisomy 13, trisomy 18, and inherited disorders • for which you request • testing but not NTDs Amniocentesis • Timing: 15–20 weeks • Tests fetal cells in a sample of amniotic fluid • Detects Down syndrome, trisomy 13, • trisomy 18, inherited disorders for which you• • • request testing, and certain types of NTDs Weeks of Pregnancy Prepregnancy First Trimester Second Trimester PFSI010: Designed as an aid to patients, this document sets forth current information and opinions related to women’s health. The information does not dictate an exclusive course of treatment or procedure to be followed and should not be construed as excluding other acceptable methods of practice. Variations, taking into account the needs of the individual patient, resources, and limitations unique to the institution or type of practice, may be appropriate. Copyright October 2016 by the American College of Obstetricians and Gynecologists. No part of this publication may be reproduced, stored in a retrieval system, posted on the Internet, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Weeks 25–28 Cell-free DNA screening • Timing: 10 weeks and beyond • Blood test • Screens for Down syndrome, trisomy 18, and, in some labs, trisomy 13 • The test is more accurate for women at high risk or who have had a positive screening test result Carrier testing • Timing: Can be done at any time but is ideally performed before pregnancy • Tests use blood or tissue sample (tissue from inside the cheek) • Detects whether you, your partner, or both carry a gene for certain genetic disorders ››› Abbreviations: CVS, chorionic villus sampling; NT, nuchal translucency; NTD, neural tube defect Note: Check your local and state laws regarding the timing and availability of prenatal genetic testing. PRENATTALL GENETTIIC TTESTTIING CHARTT   These tests can tell you the chances that your unborn baby will have certain genetic disorders. These tests can tell you whether your baby actually has certain genetic disorders. 409 12th Street SW, PO Box 96920 Washington, DC 20090-6920 Related FAQS: • Prenatal Genetic Screening Tests: • Prenatal Genetic Diagnostic Tests: › ›

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