Congenital Infections: The Complete TORCH Guide for Parents and Healthcare Providers

Toxoplasma gondii infects approximately one third of the world's population — most people silently, with no symptoms. But a first-time infection during pregnancy can allow the parasite to cross the placenta and reach the developing baby, with consequences that range from asymptomatic to severely disabling.

Diagnosis: Maternal serology — IgM (acute) and IgG (past/chronic exposure). If primary infection is confirmed, fetal diagnosis via amniocentesis with Toxoplasma PCR. Neonatal: serology + ophthalmology + neuroimaging (head CT or MRI).

Treatment: Spiramycin to prevent fetal transmission (early pregnancy). If fetal infection confirmed: pyrimethamine + sulfadiazine + folinic acid for 12 months in the newborn.

Prevention: Cook meat to safe internal temperatures. Wash all fruits and vegetables thoroughly. Wear gloves for gardening and litter box cleaning — ideally, delegate litter box duty entirely during pregnancy. Indoor cats that do not hunt pose very low risk.

Rubella is a mild, airborne viral infection in healthy adults — but in the first trimester of pregnancy, it is one of the most dangerous infections known to medicine. Up to 85 percent of babies exposed to rubella in the first trimester will develop Congenital Rubella Syndrome (CRS). The virus targets developing organ systems at their most vulnerable moments.

Prevention: The MMR vaccine (measles-mumps-rubella) is one of the safest and most effective vaccines ever developed. Two doses provide lifelong immunity. All women should confirm rubella immunity before conception. Vaccination before pregnancy eliminates this risk entirely.

The story of HIV in pregnancy is one of modern medicine's greatest achievements. Without intervention, mother-to-child transmission occurs in approximately 25 percent of pregnancies. With early diagnosis and antiretroviral therapy, that risk falls below 2 percent — and in optimal conditions, approaches zero.

Management: Antiretroviral therapy should be started as early as possible in pregnancy — ideally before conception. All HIV-positive mothers should aim for undetectable viral load at delivery. Infants should receive antiretroviral prophylaxis immediately after birth and be tested at appropriate intervals. In settings where safe formula is available and accessible, formula feeding is recommended. Where it is not, exclusive breastfeeding with maternal ART is guided by WHO recommendations.

CMV is the most common congenital infection in the world — and the most underrecognized. Approximately 0.5 to 1 percent of all babies are born with congenital CMV. Most look completely healthy at birth. But the virus can cause progressive damage — particularly to hearing — that becomes apparent only months or years later.

Diagnosis: No routine maternal screening is universally recommended. Fetal CMV is suspected when ultrasound shows brain abnormalities. Diagnosis is confirmed by amniocentesis with CMV PCR. Newborn diagnosis window: first 21 days of life — after 21 days, a positive CMV test cannot distinguish congenital from postnatal infection. Saliva PCR is the preferred newborn test.

Treatment: Symptomatic congenital CMV in newborns can be treated with valganciclovir, which has been shown to reduce the severity of progressive hearing loss. No licensed CMV vaccine is currently available, though candidates are in trials.

Prevention (behavioral): Thorough handwashing after diaper changes, wiping noses, or handling toddlers' saliva or urine. Avoid sharing food, drinks, utensils, or toothbrushes with young children. Avoid kissing young children on the mouth. Pregnant women working in daycare or pediatric settings face elevated risk and should be counseled accordingly.

Of all the infections on this list, congenital syphilis is perhaps the most tragic — because it is entirely preventable and entirely curable, and yet cases are rising in many countries. The bacterium Treponema pallidum crosses the placenta at any stage of pregnancy. Without treatment, transmission can occur in up to 80 percent of pregnancies.

Diagnosis: Non-treponemal tests (RPR or VDRL) for screening — confirmed with treponemal tests (FTA-ABS or TPPA). Newborn: RPR at delivery from infant serum (not cord blood — which can give false results). Neonatal LP and CSF VDRL if neurological involvement suspected.

The failure to prevent congenital syphilis is not a failure of medicine. It is a failure of system — failure to screen, failure to treat in time, failure to reach the most vulnerable populations. The solution is universal, repeated screening and immediate treatment.

Herpes simplex virus behaves differently from the other TORCH infections. Intrauterine transmission is rare. The primary risk is neonatal herpes — acquired when the baby passes through an infected birth canal at the time of delivery, when active genital lesions are present.

Suppressive therapy: Acyclovir 400mg PO three times daily from 36 weeks of pregnancy in women with a history of genital herpes — to reduce the likelihood of active lesions or viral shedding at delivery. This reduces the rate of cesarean section for HSV and the rate of neonatal HSV.