Toxoplasmosis in pregnancy

By trimester

Weeks 1–13

1st trimester

Transmission is least likely now, but a first-trimester infection is the one most associated with severe problems when it does reach the fetus. This is the stretch where the kitchen and garden habits earn their keep.

Weeks 14–27

2nd trimester

The middle ground on both counts. Worth knowing that undercooked meat and unwashed produce cause more infections than cats do, so the food side of the list deserves as much attention as the litter box.

Weeks 28–birth

3rd trimester

Transmission is most likely now and tends to be less severe. Babies infected late often look completely normal at birth, which is why follow-up eye and hearing checks matter more than how the newborn appears.

What does the evidence show for toxoplasmosis?

• Toxoplasmosis comes from the parasite Toxoplasma gondii, which can survive for long stretches in raw meat, unpasteurized milk, and cat feces. 1
• People pick it up three main ways: eating meat that has not been cooked properly, handling soil or cat feces that contain the parasite, and gardening without protection. 1
• When infection starts in the first trimester the fetus has a higher chance of severe problems, while later infection is more likely to pass on but tends to be milder, and congenital toxoplasmosis can affect the brain, eyes, heart, kidneys, blood, liver, or spleen. 1
• Infection is silent in about 50 percent of healthy adults, and roughly 75 percent of infants with congenital toxoplasmosis have no apparent signs at birth while remaining at risk of later eye, hearing, and developmental problems. 2
• The described exposure-lowering steps are cooking meat to a safe internal temperature using a thermometer, freezing meat for several days below 0 degrees Fahrenheit, wearing gloves for gardening and litter changes, washing all fruits and vegetables, and skipping unpasteurized dairy. 1

When should I call my provider about toxoplasmosis?

Most adults infected with toxoplasmosis have no symptoms at all, so exposure history carries more weight here than how you feel. When symptoms do surface they are swollen lymph nodes, fever, headache, or muscle pain, and that mononucleosis-like picture in pregnancy is a reason to call rather than wait out. Call after a known exposure too, even feeling fine: cleaning a litter box, eating undercooked meat, gardening without gloves, so screening and testing options can be discussed while the timing still counts. Anyone with a weakened immune system should take a new fever or headache to a provider promptly, since a previously quiet infection can become active again. If you are ever unsure which side of the line you are on, make the call. Obstetric teams handle these check-ins as routine, not as overreacting.