This blood test looks for: • Down syndrome: A blood test is performed in combination with the first ultrasound to determine the likelihood your baby will have Down’s Syndrome.Specifically, caregivers test for abnormal levels of h CG (human chorionic gonadotrophin) and PAPP-A (pregnancy associated plasma protein). (Note: Your caregiver might require you take additional tests. Talk to your caregiver if you have questions or concerns.) Tests in first trimester What to expect Your first ultrasound(s), blood and urine tests When Weeks 11 to 13 (*dating ultrasound is done sooner) Dating ultrasound Not everyone gets this scan but some caregivers offer a dating ultrasound if you’ve had bleeding in the first few weeks or had problems in prior pregnancies (miscarriages, etc.).First prenatal blood tests After your scan you’ll have blood taken.Portions of this Practice Bulletin were developed from collaborative documents with the American College of Radiology and the American Institute of Ultrasound in Medicine (1, 2).Committee on Practice Bulletins—Obstetrics and American Institute of Ultrasound in Medicine.
During this period, gestational age is by far the strongest variable affecting foetal size and the crown-rump measurement is accurate within five days.
Obstetric ultrasonography is an important and common part of obstetric care in the United States.
The purpose of this document is to present information and evidence regarding the methodology of, indications for, benefits of, and risks associated with obstetric ultrasonography in specific clinical situations.
Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to the institution or type of practice.
Copyright December 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. Received October 21, 2016 Accepted October 21, 2016 Obstetric ultrasound examinations are performed with a transabdominal, transvaginal, or transperineal approach.