What is the purpose and treatment protocol of the TORCH (Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes) test in pregnant women?

TORCH Testing in Pregnancy

Primary Recommendation

Routine universal TORCH screening is NOT recommended for all pregnant women; instead, testing should be targeted based on specific clinical indications, risk factors, or concerning ultrasound findings. 1

Evidence-Based Screening Approach by Pathogen

Mandatory Universal Screening Components

The following infections require universal screening for ALL pregnant women at the first prenatal visit:

• Syphilis: All pregnant women must receive serologic testing at the first prenatal visit using nontreponemal tests (RPR or VDRL) followed by confirmatory treponemal antibody testing 2

  • High-risk women require repeat testing at 28 weeks gestation and again at delivery 2
  • Many states mandate delivery screening; no infant should be discharged without documented maternal syphilis status 2

• Hepatitis B: Universal screening for HBsAg at the first prenatal visit is required for all pregnant women 2

• HIV: Testing should be offered to all pregnant women at the first prenatal visit, with universal screening recommended in many guidelines 2

Selective/Risk-Based Screening Components

The following infections should NOT be routinely screened in all pregnant women:

• Toxoplasmosis: Routine universal screening is NOT recommended for low-risk pregnant women 1, 3

  • Screening should only be offered to women with specific risk factors (cat exposure, consumption of raw/undercooked meat, gardening without gloves) 3
  • Testing is indicated when ultrasound findings suggest congenital infection: intracranial calcification, microcephaly, hydrocephalus, ascites, hepatosplenomegaly, or severe intrauterine growth restriction 3

• Rubella: While historically part of TORCH panels, current guidelines focus on pre-pregnancy immunity verification rather than routine pregnancy screening 4

• Cytomegalovirus (CMV): Routine universal screening is NOT recommended 1

  • Consider testing only with concerning ultrasound findings or maternal symptoms suggesting acute infection 3, 5

• Herpes Simplex Virus (HSV): Routine serologic screening is NOT recommended 2

  • Cultures at delivery may be useful for women with known recurrent genital herpes to guide neonatal management 2
  • Routine serial cultures in the third trimester are NOT indicated for asymptomatic women with history of recurrent herpes 2

Critical Testing Principles

Confirmation Requirements

All positive TORCH results from commercial laboratories MUST be confirmed at reference laboratories before any intervention, particularly for toxoplasmosis where approximately 60% of positive IgM results are false positives. 1, 3

• Suspected recent toxoplasmosis infection requires confirmation with repeat testing within 2-3 weeks 3
• Consider starting spiramycin immediately without waiting for repeat results if acute infection is suspected 3

Timing Considerations for Toxoplasmosis Testing

If amniocentesis is indicated for toxoplasmosis PCR testing:

• Do NOT perform before 18 weeks gestation 3
• Wait at least 4 weeks after suspected acute maternal infection to reduce false-negative results 3
• Amniocentesis should be offered if: (a) maternal primary infection is diagnosed, (b) serologic testing cannot confirm or exclude acute infection, or (c) abnormal ultrasound findings are present 3

Treatment Protocols When Infection is Confirmed

Toxoplasmosis Treatment

• Fetal prophylaxis: Spiramycin should be offered if maternal infection is confirmed but fetal infection is not yet documented 3
• Confirmed fetal infection: Combination therapy with pyrimethamine, sulfadiazine, and folinic acid should be offered when fetal infection is confirmed or highly suspected (usually by positive amniotic fluid PCR) 3
• Previous infection: Anti-toxoplasma treatment is NOT necessary in immunocompetent pregnant women with previous infection 3

Syphilis Treatment

• Follow-up serologic tests should be obtained after treatment to document decline in titers 2
• Use the same nontreponemal test (VDRL or RPR) for follow-up that was used initially to ensure comparable results 2

Special Populations

High-Risk Women Requiring Enhanced Surveillance

High-risk pregnant women (new or multiple partners, inconsistent condom use, living in high-prevalence areas) require:

• Repeat syphilis testing in third trimester (28 weeks) and at delivery 2
• Chlamydia and gonorrhea screening if under 25 years or at increased risk 2

Immunocompromised Women

• HIV-positive or immunosuppressed women should be offered toxoplasmosis screening due to risk of reactivation and toxoplasmosis encephalitis 3

Common Pitfalls to Avoid

1. Ordering reflexive "TORCH panels": The clinical utility of TORCH serology for non-specific ultrasound abnormalities such as isolated fetal growth restriction or isolated polyhydramnios is extremely low 5. Recent systematic review found ZERO cases of congenital toxoplasmosis, rubella, or HSV confirmed across 2,538 pregnancies tested with TORCH panels for ultrasound abnormalities 5.

2. Failing to confirm positive results: Approximately 60% of positive toxoplasmosis IgM results from commercial laboratories are false positives 1, 3. Always confirm at reference laboratories before intervention.

3. Missing high-risk women: Screening only symptomatic or high-risk women for toxoplasmosis will miss up to 50% of infected pregnant women at risk of transmission 1.

4. Inadequate syphilis follow-up: No infant should be discharged without maternal syphilis status documented at least once during pregnancy, preferably again at delivery 2.

5. Inappropriate HSV management: Prophylactic cesarean section is NOT indicated for women without active genital lesions at delivery 2.

Consultation Requirements

Each case involving a pregnant woman suspected of having acute Toxoplasma gondii infection acquired during gestation should be discussed with an expert in the management of toxoplasmosis. 3