Diagnostic approach and management algorithm of toxoplasmosis during pregnancy
Diagnostic approach and management algorithm of toxoplasmosis during pregnancy Toxoplasmosis Toxoplasmosis
«Flowchart»


Routine serologic screening is recommended during pregnancy, regardless of epidemiologic history or presence of illness during gestation1
In addition, serologic testing should be performed during pregnancy in the presence of:

o Flulike or unexplained illness

o Lymphadenopathy
o Fetal ultrasound suggestive of congenital infection


Routine serologic screening is recommended during pregnancy, regardless of epidemiologic history or presence of illness during gestation1
In addition, serologic testing should be performed during pregnancy in the presence of:

o Flulike or unexplained illness

o Lymphadenopathy
o Fetal ultrasound suggestive of congenital infection


Routine serologic screening is recommended during pregnancy, regardless of epidemiologic history or presence of illness during gestation1
In addition, serologic testing should be performed during pregnancy in the presence of:

o Flulike or unexplained illness

o Lymphadenopathy
o Fetal ultrasound suggestive of congenital infection


Routine serologic screening is recommended during pregnancy, regardless of epidemiologic history or presence of illness during gestation1
In addition, serologic testing should be performed during pregnancy in the presence of:


Routine serologic screening is recommended during pregnancy, regardless of epidemiologic history or presence of illness during gestation1 1 1
In addition, serologic testing should be performed during pregnancy in the presence of:

o Flulike or unexplained illness


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Toxoplasma IgG and IgM Can be
performed at nonreference, hospital-based,
or commercial laboratory
Toxoplasma IgG and IgM Can be
performed at nonreference, hospital-based,
or commercial laboratory
Toxoplasma IgG and IgM Can be
performed at nonreference, hospital-based,
or commercial laboratory


If seroconversion documented or reference laboratory confirms acute infection acquired during pregnancy:


    Treatment 5 should be promptly instituted: (a) Spiramycin6 if infection acquired before 18 wk gestation or (b) Pyrimethamine7 plus sulfadiazine plus folinic acid8 if acquired at or after 18 wk
    If safe and feasible, amniotic fluid obtained at 18 wk or onward should be tested for toxoplasma PCR
    . Fetal ultrasound should be obtained for the detection of abnormalities suggestive of C.T.
    Switch spiramycin to pyrimethamine plus sulfadiazine plus folinic acid if amniotic fluid PCR is positive or ultrasound is abnormal
    Consider testing close household contacts for the diagnosis of acute toxoplasma infection or toxoplasmosis in individuals at high

If seroconversion documented or reference laboratory confirms acute infection acquired during pregnancy:


    Treatment 5 should be promptly instituted: (a) Spiramycin6 if infection acquired before 18 wk gestation or (b) Pyrimethamine7 plus sulfadiazine plus folinic acid8 if acquired at or after 18 wk
    If safe and feasible, amniotic fluid obtained at 18 wk or onward should be tested for toxoplasma PCR
    . Fetal ultrasound should be obtained for the detection of abnormalities suggestive of C.T.
    Switch spiramycin to pyrimethamine plus sulfadiazine plus folinic acid if amniotic fluid PCR is positive or ultrasound is abnormal
    Consider testing close household contacts for the diagnosis of acute toxoplasma infection or toxoplasmosis in individuals at high

If seroconversion documented or reference laboratory confirms acute infection acquired during pregnancy:


    Treatment 5 should be promptly instituted: (a) Spiramycin6 if infection acquired before 18 wk gestation or (b) Pyrimethamine7 plus sulfadiazine plus folinic acid8 if acquired at or after 18 wk
    If safe and feasible, amniotic fluid obtained at 18 wk or onward should be tested for toxoplasma PCR
    . Fetal ultrasound should be obtained for the detection of abnormalities suggestive of C.T.
    Switch spiramycin to pyrimethamine plus sulfadiazine plus folinic acid if amniotic fluid PCR is positive or ultrasound is abnormal
    Consider testing close household contacts for the diagnosis of acute toxoplasma infection or toxoplasmosis in individuals at high

If seroconversion documented or reference laboratory confirms acute infection acquired during pregnancy:



    Treatment 5 should be promptly instituted: (a) Spiramycin6 if infection acquired before 18 wk gestation or (b) Pyrimethamine7 plus sulfadiazine plus folinic acid8 if acquired at or after 18 wk
    If safe and feasible, amniotic fluid obtained at 18 wk or onward should be tested for toxoplasma PCR
    . Fetal ultrasound should be obtained for the detection of abnormalities suggestive of C.T.
    Switch spiramycin to pyrimethamine plus sulfadiazine plus folinic acid if amniotic fluid PCR is positive or ultrasound is abnormal
    Consider testing close household contacts for the diagnosis of acute toxoplasma infection or toxoplasmosis in individuals at high

Treatment 5 should be promptly instituted: (a) Spiramycin6 if infection acquired before 18 wk gestation or (b) Pyrimethamine7 plus sulfadiazine plus folinic acid8 if acquired at or after 18 wk 5 5 6 6 7 7 8 8
If safe and feasible, amniotic fluid obtained at 18 wk or onward should be tested for toxoplasma PCR
. Fetal ultrasound should be obtained for the detection of abnormalities suggestive of C.T.
Switch spiramycin to pyrimethamine plus sulfadiazine plus folinic acid if amniotic fluid PCR is positive or ultrasound is abnormal
Consider testing close household contacts for the diagnosis of acute toxoplasma infection or toxoplasmosis in individuals at high
No serologic evidence
of toxoplasma infection.
Risk of C.T. only if woman
acquires infection during pregnancy.
Counseling should be provided
on how to avoid primary T. gondii infection.
No serologic evidence
of toxoplasma infection.
Risk of C.T. only if woman
acquires infection during pregnancy.
Counseling should be provided
on how to avoid primary T. gondii infection.
No serologic evidence
of toxoplasma infection.
Risk of C.T. only if woman
acquires infection during pregnancy.
Counseling should be provided
on how to avoid primary T. gondii infection.






If 18 wk gestation Infection acquired in the distant past and before gestation. Risk for C.T. essentially zero unless patient is immunocompromised.
If >18 wk gestation It is diffcult to establish whether infection occurred during or before pregnancy


If 18 wk gestation Infection acquired in the distant past and before gestation. Risk for C.T. essentially zero unless patient is immunocompromised.
If >18 wk gestation It is diffcult to establish whether infection occurred during or before pregnancy


If 18 wk gestation Infection acquired in the distant past and before gestation. Risk for C.T. essentially zero unless patient is immunocompromised.
If >18 wk gestation It is diffcult to establish whether infection occurred during or before pregnancy


If 18 wk gestation Infection acquired in the distant past and before gestation. Risk for C.T. essentially zero unless patient is immunocompromised.
If >18 wk gestation It is diffcult to establish whether infection occurred during or before pregnancy


If 18 wk gestation Infection acquired in the distant past and before gestation. Risk for C.T. essentially zero unless patient is immunocompromised. If 18 wk gestation
If >18 wk gestation It is diffcult to establish whether infection occurred during or before pregnancy If >18 wk gestation
Follow-up testing during
gestation to detect seroconversion2
Follow-up testing during
gestation to detect seroconversion2
Follow-up testing during
gestation to detect seroconversion2

2 2
If seroconversion detected
(i.e., IgG pos, IgM pos) ,
follow IgM-pos algorithm
If seroconversion detected
(i.e., IgG pos, IgM pos) ,
follow IgM-pos algorithm
If seroconversion detected
(i.e., IgG pos, IgM pos) ,
follow IgM-pos algorithm



If 18 wk gestation No further action required
If >18 wk gestation Attempt to obtain earlier serum for testing or results of previous toxoplasma serologic tests obtained before current pregnancy3 and consult reference laboratory.


If 18 wk gestation No further action required
If >18 wk gestation Attempt to obtain earlier serum for testing or results of previous toxoplasma serologic tests obtained before current pregnancy3 and consult reference laboratory.


If 18 wk gestation No further action required
If >18 wk gestation Attempt to obtain earlier serum for testing or results of previous toxoplasma serologic tests obtained before current pregnancy3 and consult reference laboratory.


If 18 wk gestation No further action required
If >18 wk gestation Attempt to obtain earlier serum for testing or results of previous toxoplasma serologic tests obtained before current pregnancy3 and consult reference laboratory.


If 18 wk gestation No further action required If 18 wk gestation
If >18 wk gestation Attempt to obtain earlier serum for testing or results of previous toxoplasma serologic tests obtained before current pregnancy3 and consult reference laboratory. If >18 wk gestation 3 3
Up to 50% of women who acquire Toxoplasma infection during gestation do not have a known risk factor for acute infection or an illness suggestive of toxoplasmosis. Thus, to identify all women at risk, serologic screening should be performed in all pregnant women, along with other routine screening tests.
Up to 50% of women who acquire Toxoplasma infection during gestation do not have a known risk factor for acute infection or an illness suggestive of toxoplasmosis. Thus, to identify all women at risk, serologic screening should be performed in all pregnant women, along with other routine screening tests.
Up to 50% of women who acquire Toxoplasma infection during gestation do not have a known risk factor for acute infection or an illness suggestive of toxoplasmosis. Thus, to identify all women at risk, serologic screening should be performed in all pregnant women, along with other routine screening tests.
Consider sending serum sample to a reference laboratory (e.g., PAMF-TSL).
Consider sending serum sample to a reference laboratory (e.g., PAMF-TSL).
Consider sending serum sample to a reference laboratory (e.g., PAMF-TSL).
gG neg IgM neg
gG neg IgM neg
gG neg IgM neg
IgG pos IgM neg
IgG pos IgM neg
IgG pos IgM neg
IgM pos or equivocal.
Send serum to a reference
laboratory for confirmatory testing.4
IgM pos or equivocal.
Send serum to a reference
laboratory for confirmatory testing.4


4 4 IgM pos or equivocal
In a recent study from Lyon, France, monthly screening of seronegative pregnant women was reported to significantly decrease the risk of vertical transmission and of clinical signs at 3 yr of age.
In a recent study from Lyon, France, monthly screening of seronegative pregnant women was reported to significantly decrease the risk of vertical transmission and of clinical signs at 3 yr of age.
In a recent study from Lyon, France, monthly screening of seronegative pregnant women was reported to significantly decrease the risk of vertical transmission and of clinical signs at 3 yr of age.
Consider consultation with a physician expert in management of toxoplasmosis during pregnancy (e.g., in the U.S., Palo Alto Medical Foundation-Toxoplasma Serology Laboratory [PAMF-TSL], www.pamf.org/serology/; 650-853-4828; e-mail, [email protected]; or U.S. [Chicago] National Collaborative Treatment Trial Study [NCCTS]).
Consider consultation with a physician expert in management of toxoplasmosis during pregnancy (e.g., in the U.S., Palo Alto Medical Foundation-Toxoplasma Serology Laboratory [PAMF-TSL], www.pamf.org/serology/; 650-853-4828; e-mail, [email protected]; or U.S. [Chicago] National Collaborative Treatment Trial Study [NCCTS]).
Consider consultation with a physician expert in management of toxoplasmosis during pregnancy (e.g., in the U.S., Palo Alto Medical Foundation-Toxoplasma Serology Laboratory [PAMF-TSL], www.pamf.org/serology/; 650-853-4828; e-mail, [email protected]; or U.S. [Chicago] National Collaborative Treatment Trial Study [NCCTS]).
Treatment regimens vary by country. The pyrimethamine-sulfadiazine-folinic acid regimen should not be offered to any pregnant woman before 12 wk of gestation because of potential teratogenicity. In some centers in Europe, this regimen is offered at 14 wk of gestation or later; in the U.S., it is recommended at 18 wk or later.
Treatment regimens vary by country. The pyrimethamine-sulfadiazine-folinic acid regimen should not be offered to any pregnant woman before 12 wk of gestation because of potential teratogenicity. In some centers in Europe, this regimen is offered at 14 wk of gestation or later; in the U.S., it is recommended at 18 wk or later.
Treatment regimens vary by country. The pyrimethamine-sulfadiazine-folinic acid regimen should not be offered to any pregnant woman before 12 wk of gestation because of potential teratogenicity. In some centers in Europe, this regimen is offered at 14 wk of gestation or later; in the U.S., it is recommended at 18 wk or later.
Spiramycin is not commercially available in the U.S. It can be obtained at no cost and after consultation (with PAMF-TSL or the NCCTS through the U.S. Food and Drug Administration).
Spiramycin is not commercially available in the U.S. It can be obtained at no cost and after consultation (with PAMF-TSL or the NCCTS through the U.S. Food and Drug Administration).
Spiramycin is not commercially available in the U.S. It can be obtained at no cost and after consultation (with PAMF-TSL or the NCCTS through the U.S. Food and Drug Administration).
When using pyrimethamine, folic acid should be discontinued from the prenatal multivitamins. Folic acid can potentially counteract the antiparasitic effect of the drug.
When using pyrimethamine, folic acid should be discontinued from the prenatal multivitamins. Folic acid can potentially counteract the antiparasitic effect of the drug.
When using pyrimethamine, folic acid should be discontinued from the prenatal multivitamins. Folic acid can potentially counteract the antiparasitic effect of the drug.



Folic acid should not be erroneously used instead of folinic acid. (From Bennett JE et al: Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, ed 9, Philadelphia, 2020, Elsevier.)
Folic acid should not be erroneously used instead of folinic acid. (From Bennett JE et al: Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, ed 9, Philadelphia, 2020, Elsevier.)
Folic acid should not be erroneously used instead of folinic acid. (From Bennett JE et al: Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, ed 9, Philadelphia, 2020, Elsevier.)