Congenital and perinatally acquired infections

Overview & Definition

Congenital and perinatally acquired infections are infections transmitted from mother to child during pregnancy, labour, delivery, or the early postnatal period. They range from clinically silent to lethal, and the damage they cause is determined less by the identity of the organism alone than by the timing of infection, the inoculum, and the maturity of the fetal immune response. The classical mnemonic TORCH - Toxoplasmosis, Other (syphilis, varicella, parvovirus), Rubella, Cytomegalovirus, and Herpes simplex - is a useful entry point, but it understates the modern list, which now firmly includes Zika virus and Chagas disease alongside the preventable perinatally transmitted hepatitis B, hepatitis C, and human immunodeficiency virus. [10]

A congenital infection is acquired in utero, almost always before birth, via transplacental haematogenous spread or ascending infection through ruptured or intact membranes. A perinatally acquired infection is contracted during passage through the birth canal or in the immediate postnatal period, while postnatally acquired infection is transmitted after birth through breastfeeding, blood exposure, or close contact. The distinction matters: congenital infection produces the structural and neurodevelopmental malformations of the TORCH phenotype, whereas perinatal acquisition more often causes acute neonatal disease such as disseminated herpes simplex or early-onset bacterial sepsis. [10]

Cytomegalovirus is the commonest congenital infection in developed countries, affecting around 0.5 to 1 per cent of all live births, and it is the leading non-genetic cause of sensorineural hearing loss and neurodevelopmental disability in children. By contrast, rubella - once the archetypal teratogen - has been driven to near-elimination by universal vaccination, and congenital rubella syndrome is now a disease of unvaccinated populations and migrant communities. Congenital syphilis, however, is resurgent globally and demands vigilance. [7]

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1. [1]Kimberlin DW Valganciclovir for symptomatic congenital cytomegalovirus disease. N Engl J Med, 2015.PMID 25738669
2. [2]Thiébaut R, Leproust S, Chêne G, et al. Effectiveness of prenatal treatment for congenital toxoplasmosis: a meta-analysis of individual patients' data. Lancet, 2007.PMID 17223474
3. [3]Corey L Once-daily valacyclovir to reduce the risk of transmission of genital herpes. N Engl J Med, 2004.PMID 14702423
4. [4]Nielsen-Saines K Three postpartum antiretroviral regimens to prevent intrapartum HIV infection. N Engl J Med, 2012.PMID 22716975
5. [5]Enders M Fetal morbidity and mortality after acute human parvovirus B19 infection in pregnancy: prospective evaluation of 1018 cases. Prenat Diagn, 2004.PMID 15300741
6. [6]Fan L Cost-effectiveness of active-passive prophylaxis and antiviral prophylaxis during pregnancy to prevent perinatal hepatitis B virus infection. Hepatology, 2016.PMID 26509655
7. [7]Gilmour LS Congenital syphilis: a review of global epidemiology. Clin Microbiol Rev, 2023.PMID 36920205
8. [8]Freitas DA Congenital Zika syndrome: a systematic review. PLoS One, 2020.PMID 33320867
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10. [10]Moodley A The term newborn: congenital infections. Clin Perinatol, 2021.PMID 34353577