Table 3. Transplacental infections: screening and diagnostic testing.

	Cytomegalovirus	Parvovirus B19	Toxoplasmosis	Syphilis
•Screening as recommended by the Mu-RL*	•Screening not recommended	•Screening not recommended	•Screening not recommended	Serological screening in early pregnancy (syphilis screening test)
•Tests for pregnant women	•Basic testing: CMV IgG/IgM •Confirmatory/advanced testing depending on findings and clinical questions: additional serological tests (e.g., IgG avidity, immunoblot), possibly via PCR in multiple specimens, follow-up monitoring	•Basic testing: B19V IgG/IgM •Confirmatory/advanced testing depending on findings and clinical questions; detection of B19V via quantitative PCR; additional serological tests (e.g., IgG avidity), follow-up monitoring	•Basic testing: Toxoplasma IgG/IgM •Confirmatory/advanced testing depending on findings and clinical questions; additional serological tests or follow-up monitoring	A positive screening test is confirmed with a second test to detect Treponema-specific antibodies; to assess virulence → detection of Treponema-specific IgM antibodies and non-specific cardiolipin antibodies
•Tests for the fetus	•Detection of CMV in amniotic fluid via quantitative PCR	•If necessary, detection of B19V in fetal blood via PCR (as part of intrauterine transfusion). Detection is also possible in amniotic fluid and chorionic villi	•If necessary, detection of Toxoplasma in amniotic fluid via PCR	Detection of Treponema pallidum in amniotic fluid and fetal blood via PCR. Detection of Treponema-specific IgM antibodies and cardiolipin antibodies in fetal blood
•Tests for the neonate	•Gold standard: Detection of CMV in urine via quantitative PCR (as early as possible after birth, no later than the 3rd week of life). A positive pathogen detection in saliva/oral secretions must be confirmed by urine testing; a negative pathogen detection in saliva/oral secretions rules out a cCMV infection in > 96% of cases.	•Only in symptomatic neonates: B19V PCR	•Determination of Toxoplasma IgM and IgA antibodies •Determination of the “motherchild profile” (comparative IgG immunoblot) as indicated, pathogen detection (PCR) in various materials as indicated, CSF testing, IgG follow-up testing in the infant until maternal antibodies are no longer detectable	Quantitative determination of cardiolipin antibodies in serum Determination of Treponema-specific IgM antibodies PCR in various materials as indicated, CSF as indicated, serological follow-up in the infant until maternal antibodies are no longer detectable

^*The Mu_RL (13) stipulates the following serological tests as standard services covered by statutory health insurance in Germany: syphilis (screening with TPHA or TPPA), HIV antibody test, rubella antibody test, hepatitis B (HBsAg detection). Serological testing for toxoplasmosis is not routinely foreseen in the maternity guidelines; it is performed only in case of suspicion or offered as an individual health service. Screening tests for CMV, B19V, and other transplacental infections are not part of the standard maternity guidelines but are performed when clinically indicated or in case of suspicion.

Ab, antibody; B19V, parvovirus B19; cCMV, congenital cytomegalovirus infection; CMV, cytomegalovirus; CSF, cerebrospinal fluid; Ig, immunoglobulin; LSR, syphilis serology test; Mu_RL, G-BA Maternity Guidelines; PCR, nucleic acid amplification via polymerase chain reaction; TPHA, Treponema pallidum hemagglutination assay; TPPA, Treponema pallidum particle agglutination assay