Congenital (TORCH) infections: syphilis, toxoplasmosis, CMV and Zika !

Infections passed from mother to baby during pregnancy that can harm the brain, eyes, ears and liver. Prenatal screening prevents or treats many of them.

Updated 2026-11-01

Structures involved

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Microorganisms that cause it

In embryology

Why it happens

What it is

A group of infections transmitted from the mother to the fetus across the placenta (or at birth) that can cause miscarriage, stillbirth, prematurity and birth defects. The acronym TORCH covers Toxoplasma, Other agents (syphilis, varicella, parvovirus B19, Zika, HIV), Rubella, Cytomegalovirus (CMV) and Herpes simplex.

Who gets it

CMV is the most common congenital infection worldwide and a leading non-genetic cause of hearing loss in children. Congenital syphilis has risen in the Americas and is one of the conditions PAHO aims to eliminate (EMTCT Plus), a stated priority for Colombia. Toxoplasma infection is common in Colombia, and the country was among the most affected by the 2015–2016 Zika epidemic, which revealed congenital Zika syndrome.

Causes

Treponema pallidum (syphilis): transplacental at any stage of pregnancy, highest risk with untreated primary or secondary maternal syphilis
Toxoplasma gondii: acute maternal infection from undercooked meat, contaminated water or soil, or cat faeces
Cytomegalovirus: primary maternal infection or reactivation/reinfection; spread by saliva and urine of young children
Zika virus: Aedes mosquito bite or sexual transmission during pregnancy
Others in the group: rubella, herpes simplex, varicella, parvovirus B19 and HIV

Risk factors

Absent, late or incomplete prenatal care and screening
Untreated or inadequately treated maternal syphilis, or untreated sexual partners
Eating raw or undercooked meat, drinking untreated water, handling soil or cat litter
Close contact with saliva and urine of toddlers (CMV), e.g. mothers of children in day care
Living in or travelling to areas with Aedes mosquitoes during an outbreak (Zika)
Infection early in pregnancy, which usually causes more severe damage (except toxoplasma, which is transmitted more often late)

Pathophysiology

The organism crosses the placenta and infects fetal tissues while organs are forming, causing inflammation, cell death and calcification. Damage to the developing brain (periventricular or diffuse calcifications, ventricular dilation, microcephaly), the retina and choroid, the inner ear, the liver and the bone marrow explains the shared picture. Early infection tends to cause structural defects; later infection more often causes active disease at birth.

Classification

Congenital syphilis: early (before 2 years) and late (after 2 years)
Congenital toxoplasmosis: classic triad of chorioretinitis, hydrocephalus and diffuse intracranial calcifications
Congenital CMV: periventricular calcifications, microcephaly and sensorineural hearing loss; symptomatic or asymptomatic at birth
Congenital Zika syndrome: severe microcephaly with a collapsed skull, subcortical calcifications, eye lesions and joint contractures
Congenital rubella: cataracts, sensorineural deafness and patent ductus arteriosus

Symptoms and signs

Many newborns look normal at birth, especially with CMV and toxoplasma
Low birth weight, prematurity, jaundice, enlarged liver and spleen, petechiae or a «blueberry muffin» rash
Small head (microcephaly), seizures, poor feeding or abnormal tone
Early syphilis: persistent bloody nasal discharge («snuffles»), a peeling rash on palms and soles, bone pain with pseudoparalysis
Late syphilis: notched incisors (Hutchinson teeth), saddle nose, sabre shins, interstitial keratitis and deafness
Eye findings: chorioretinitis, cataract or microphthalmia; hearing loss that may appear or worsen later

Diagnosis

Clinical: Maternal history (prenatal serologies, treatment, exposures, travel) plus a full newborn examination: head circumference, liver and spleen, skin, eyes (dilated fundus) and hearing screening.
Tests: Maternal and infant syphilis serology (non-treponemal titres compared with the mother's, plus treponemal tests); toxoplasma IgG/IgM/IgA; CMV PCR in urine or saliva within the first 3 weeks of life (later results cannot separate congenital from acquired infection); Zika PCR and IgM; blood count, liver enzymes, bilirubin; CSF study when neurosyphilis or CNS involvement is suspected.
Imaging: Cranial ultrasound, CT or MRI for calcifications, ventricular dilation and brain malformations; long-bone X-rays in congenital syphilis (periostitis, metaphysitis); prenatal ultrasound may show microcephaly, calcifications or hydrops.

Differential diagnosis

Neonatal bacterial sepsis
Genetic or metabolic causes of microcephaly or hepatosplenomegaly
Haemolytic disease of the newborn
Pseudo-TORCH syndromes (genetic interferonopathies with intracranial calcifications)
Hypoxic-ischaemic encephalopathy

Goal of treatment

Prevent transmission by screening and treating the mother, treat the infected newborn early to limit damage, and detect and support hearing, vision and developmental problems.

Treatment

Medical: Syphilis: penicillin treats the pregnant woman (and her partners) and the infected or exposed newborn; it is the only treatment considered adequate to prevent congenital syphilis.
Medical: Toxoplasmosis: spiramycin during pregnancy to reduce transmission; pyrimethamine plus sulfadiazine with folinic acid when fetal infection is confirmed and for the infected infant.
Medical: CMV: antivirals (ganciclovir or valganciclovir) are considered for newborns with symptomatic disease, especially CNS involvement or hearing loss; Zika has no specific antiviral and care is supportive.
Follow-up: Repeated hearing and eye examinations, head growth, neurodevelopmental follow-up and serologic follow-up to confirm cure in syphilis.
Rehabilitation: Early stimulation, physiotherapy, hearing aids or cochlear implants, and seizure management according to the deficits.

Complications

Sensorineural hearing loss, which can be progressive (CMV, rubella, syphilis)
Visual loss from chorioretinitis, cataract or optic atrophy
Hydrocephalus, epilepsy, cerebral palsy and intellectual disability
Stillbirth, prematurity and neonatal death
Late syphilis stigmata: dental, nasal, bony and corneal deformities

Prognosis

Depends on the agent and timing. Congenital syphilis is fully preventable and curable when found early, while untreated it causes lasting damage or death. Symptomatic CMV, congenital toxoplasmosis with brain lesions and congenital Zika syndrome often leave permanent neurological, visual or hearing sequelae.

Prevention

Syphilis and HIV screening at the first prenatal visit, in the third trimester and at delivery, with treatment of the woman and her partners
Food and water hygiene: well-cooked meat, washed vegetables, avoiding cat litter and soil without gloves
Handwashing after contact with young children's saliva, urine or nappies
Mosquito control and protection from bites during pregnancy in Zika areas
Rubella vaccination before pregnancy

Test yourself

Think of the answer, then tap the question to see it.

What is the classic triad of congenital toxoplasmosis?

Chorioretinitis, hydrocephalus and diffuse intracranial calcifications.

Which congenital infection typically causes periventricular calcifications and sensorineural hearing loss?

Cytomegalovirus (CMV), the most common congenital infection.

Which drug is the only treatment considered adequate in pregnancy to prevent congenital syphilis?

Penicillin, given to the pregnant woman (and her partners) early enough before delivery.

What are two late signs of congenital syphilis?

Hutchinson teeth (notched incisors), saddle nose, sabre shins, interstitial keratitis or eighth-nerve deafness.

What are the hallmark features of congenital Zika syndrome?

Severe microcephaly with a collapsed skull, subcortical calcifications, eye lesions, hearing loss and joint contractures.

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Educational information, not medical advice. For any symptom, see a health professional.

Sources: Congenital syphilis: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Congenital toxoplasmosis: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Zika virus (World Health Organization, 2022).

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Representative model, for educational purposes only.

White matter highlighted on the Durgical 3D model