Acute toxoplasmosis infection during pregnancy affects roughly 1.1% of pregnancies worldwide, though rates vary significantly by region. Congenital toxoplasmosis, where the infection passes from mother to baby, occurs in an estimated 1.5 per 1,000 live births globally, adding up to about 190,100 cases each year.
Global and Regional Rates
The risk of acquiring a new toxoplasmosis infection during pregnancy is not the same everywhere. A meta-analysis of global data found the overall incidence of acute infection during pregnancy is about 1.1%. In European countries, the rate drops to around 0.5%, while in the Eastern Mediterranean region it climbs to 2.5%. These differences reflect variations in climate, food preparation habits, and the prevalence of the parasite in local soil and animal populations.
In the United States, the picture is harder to pin down. Toxoplasmosis is not a nationally notifiable disease, meaning there is no centralized public health surveillance tracking cases across the country. What data exists comes from individual state-level reporting efforts, making a reliable national estimate difficult. Europe’s rate of congenital toxoplasmosis sits at roughly 0.5 per 1,000 live births, with a disease burden of 2.8 disability-adjusted life years per 1,000 births.
How the Infection Reaches the Baby
Not every pregnant person who contracts toxoplasmosis passes it to their baby. The likelihood of vertical transmission (mother to fetus) depends heavily on when during pregnancy the infection occurs. In the first trimester, transmission rates are low, between 2% and 15%. By the second trimester, the risk rises to around 18%. In the third trimester, it jumps to as high as 70%.
There’s an important tradeoff here. While transmission is most likely late in pregnancy, infections acquired early tend to cause far more serious harm to the developing baby. The fetus is most vulnerable during the first trimester, when organ systems are forming. Infections in the third trimester are more frequently transmitted but less likely to cause severe damage, because the baby is further along in development.
What Happens When a Baby Is Infected
In a large study following 666 live-born children whose mothers were infected during pregnancy, 17% (112 children) had confirmed congenital toxoplasmosis. Of those followed long-term, 74% were asymptomatic, meaning they showed no obvious signs of the infection at birth or during follow-up. About 26% developed chorioretinitis, an eye condition that causes inflammation of the retina and can affect vision. Only one child in the study had serious neurological involvement.
The most severe outcomes, including hydrocephalus (fluid buildup in the brain) and severe growth restriction, are typically detectable on prenatal ultrasound. These cases are rare, but when major brain abnormalities are identified before birth, termination of pregnancy may be discussed as an option depending on the severity and the family’s circumstances.
Many children with congenital toxoplasmosis who appear healthy at birth still need long-term monitoring. Chorioretinitis can develop months or even years after delivery, so follow-up eye exams are a standard part of care for affected children.
How Pregnant People Get Infected
Cat litter gets most of the attention, but it is only one of several routes of infection. The parasite, Toxoplasma gondii, lives in soil, water, and undercooked meat. In practical terms, the most common exposures include:
- Undercooked or raw meat, particularly pork, lamb, and venison, which can harbor tissue cysts of the parasite
- Unwashed fruits and vegetables grown in or contaminated by soil containing infected cat feces
- Gardening without gloves, since soil and sand can be contaminated even if you don’t own a cat
- Untreated water, especially when traveling in less developed regions
- Raw shellfish like oysters, mussels, and clams
- Cat litter boxes, because cats shed the parasite in their feces after catching infected prey
Many people assume the biggest risk is living with a cat, but a cat that stays indoors and eats commercial food is unlikely to be shedding the parasite. The greater everyday risk for most people is handling raw meat or soil without proper hand-washing afterward.
Reducing Your Risk During Pregnancy
Because there is no routine vaccine and screening practices vary by country, prevention is largely behavioral. The CDC recommends cooking meat to safe internal temperatures using a food thermometer. Freezing meat at sub-zero temperatures (0°F or below) for several days before cooking also greatly reduces the chance of infection.
Rinse all fruits and vegetables under running water before eating them, or cook them. Avoid unpasteurized goat’s milk and raw shellfish. When gardening or working with soil or sand, wear gloves and wash your hands thoroughly with soap and water afterward. Clean kitchen surfaces with hot, soapy water after preparing raw meat.
If you have a cat, have someone else change the litter box during your pregnancy. If that is not possible, change it daily, because the parasite typically needs one to five days after being shed to become infectious. Wearing gloves and washing your hands immediately after are additional precautions. Keeping your cat indoors reduces the chance it will encounter infected prey in the first place.