Q: I am 8 weeks pregnant and my blood tested positive for toxoplasmosis. What does this mean?
A: The initial test for toxoplamosis is an antibody test for IgG. Among American women of childbearing age, 40-50% carry IgG antibodies against the parasite because they've been exposed to it in the past. Testing positive for the IgG toxoplasma antibody usually means they are immune and are unlikely to infect the fetus. After an initial infection with Toxoplasma gondii, you'll test positive for the IgG antibody forever. Most likely, you became infected before your pregnancy and need not worry. Having the antibody makes you partially immune, so there's little chance that you would infect your fetus. There is another toxoplasma antibody test called IgM. The IgM test signifies a more recent infection, maybe up to one to two years ago, though it's difficult to be exact.