Back to Search Results


Toxoplasmosis in Pregnancy

Author: Michael L. Socol, MD

Editor: Timothy Klatt, MD

Registered users can also download a PDF or listen to a podcast of this Pearl.
Log in now, or create a free account to access bonus Pearls features.

Toxoplasma gondii is a protozoan which can lead to human infection through infected uncooked meat, exposure to contaminated soil or water, eating soil contaminated fruits or vegetables, or exposure to infected cat feces.  Most infections are asymptomatic.  When symptoms occur they are usually nonspecific and mild.  Bilateral, symmetrical, nontender cervical lymphadenopathy is the most common symptom.    Immunocompromised hosts (e.g. HIV infected individuals) can manifest such problems as central nervous system infection, myocarditis, or pneumonitis. The diagnosis is made by serology showing seroconversion from negative to positive IgM or IgG antibodies.  Conversion requires confirmation in a reference laboratory.  Maternal IgG avidity testing may also be useful to assist with timing the primary infection for patient counseling.

Congenital infection is most likely to occur following maternal infection in the third trimester, although first trimester fetal infection is  more likely to lead to clinical sequelae.  Most infected fetuses are asymptomatic at birth.  Characteristic ultrasound findings include hyperechoic intracranial calcifications and cerebral ventriculomegaly, which carry a poor prognosis.  The diagnosis of congenital infection can be confirmed by PCR of amniotic fluid.  Uncertainty surrounding treatment efficacy persists, although treatment is generally recommended.  Treatment may include pyrimethamine, sulfadiazine and folinic acid in addition to using spiramycin to reduce transplacental transfer of the parasite.  Efforts in the United States are primarily directed toward prevention of infection rather than routine screening.  Careful hand washing, washing of fruits and vegetables, and avoidance of cat litter or uncooked meat are all advised.

Further Reading:

Duff P, Creasy RK, Resnik R, et al., Maternal-Fetal Medicine: Principles and Practice. Maternal and fetal infections.  8th Edition, Saunders, 2018.

American College of Obstetricians and Gynecologists, Practice bulletin no. 151: Cytomegalovirus, parvovirus B19, varicella zoster, and toxoplasmosis in pregnancy. Obstet Gynecol. 2015 Jun;125(6):1510-25. doi: 10.1097/01.AOG.0000466430.19823.53.

Initial approval October 2008. Revised January 2015. Revised July 2016. Reaffirmed January 2018. Revised July 2019, Reaffirmed May 2021


********** Notice Regarding Use ************

The Society for Academic Specialists in General Obstetrics and Gynecology, Inc. (“SASGOG”) is committed to accuracy and will review and validate all Pearls on an ongoing basis to reflect current practice.

This document is designed to aid practitioners in providing appropriate obstetric and gynecologic care. Recommendations are derived from major society guidelines and high-quality evidence when available, supplemented by the opinion of the author and editorial board when necessary. It should not be construed as dictating an exclusive course of treatment or procedure to be followed.

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. SASGOG reviews the articles regularly; however, its publications may not reflect the most recent evidence. While we make 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. SASGOG does not guarantee, warrant, or endorse the products or services of any firm, organization, or person. Neither SASGOG nor its respective 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 2021 The Society for Academic Specialists in General Obstetrics and Gynecology, Inc. All rights reserved. No re-print, duplication or posting allowed without prior written consent.


Back to Search Results