When any fetal blood group factor inherited from the father is not possessed by the mother, antepartum or intrapartum fetal–maternal bleeding may stimulate an immune reaction in the mother. Maternal immune reactions also can occur from blood product transfusion. The formation of maternal antibodies, or “alloimmunization,” may lead to various degrees of transplacental passage of these antibodies into the fetal circulation. Depending on the degree of antigenicity and the amount and type of antibodies involved, this transplacental passage may lead to hemolytic disease in the fetus and neonate. Undiagnosed and untreated, alloimmunization can lead to significant perinatal morbidity and mortality. Advances in Doppler ultrasonography have led to the development of noninvasive methods of management of alloimmunization in pregnant women. Together with more established protocols, Doppler ultrasound evaluation may allow for a more thorough and less invasive workup with fewer risks to the mother and fetus. Prevention of alloimmunization is addressed in another Practice Bulletin (1).
Committee on Practice Bulletins—Obstetrics. This Practice Bulletin was developed by the American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Obstetrics with the assistance of Calla Holmgren, MD, and T. Flint Porter, MD.
INTERIM UPDATE: This Practice Bulletin is updated as highlighted to reflect a limited, focused change to align with Practice Bulletin No. 181, Prevention of Rh D Alloimmunization.
This information is designed as an educational resource to aid clinicians in providing obstetric and gynecologic care, and use of this information is voluntary. This information should not be considered as inclusive of all proper treatments or methods of care or as a statement of the standard of care. It is not intended to substitute for the independent professional judgment of the treating clinician. Variations in practice may be warranted when, in the reasonable judgment of the treating clinician, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology. The American College of Obstetricians and Gynecologists reviews its publications regularly; however, its publications may not reflect the most recent evidence. Any updates to this document can be found onwww.acog.orgor by calling the ACOG Resource Center.
While ACOG makes every effort to present accurate and reliable information, this publication is provided “as is” without any warranty of accuracy, reliability, or otherwise, either express or implied. ACOG does not guarantee, warrant, or endorse the products or services of any firm, organization, or person. Neither ACOG nor its officers, directors, members, employees, or agents will be liable for any loss, damage, or claim with respect to any liabilities, including direct, special, indirect, or consequential damages, incurred in connection with this publication or reliance on the information presented.
Copyright March 2018 by the American College of Obstetricians and Gynecologists. All rights reserved. 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 therwise, without prior written permission from the publisher.
Requests for authorization to make photocopies should be directed to Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400.
American College of Obstetricians and Gynecologists 409 12th Street, SW, PO Box 96920, Washington, DC 20090-6920
Management of alloimmunization during pregnancy. ACOG Practice Bulletin No. 192. American College of Obstetricians and Gyne-cologists. Obstet Gynecol 2018;131:e82–90.