Infection in the early part of pregnancy is less likely to be transmitted to the fetus, but when infection does occur early on it results in severe birth defects or miscarriage. Later in pregnancy the organism is more likely to infect the fetus but less likely to cause damage. Although a couple of medications are available to treat the infection, they are rarely used during pregnancy because they may be toxic to the fetus or cause birth defects. One medication that is used in Europe, spiramycin, seems to be safe for use in pregnancy, though it has not yet been approved by the Federal Drug Administration. However, it may be obtained by women here under special circumstances.
Prevention is certainly the best course.
If you're planning to conceive, and you have a cat or eat uncooked meats, have your blood tested. If you're immune, you won't have to worry about exposure to toxoplasmosis during your pregnancy. Otherwise, have another family member deal with the litter box. Don't allow your cat to walk on areas where food is prepared, and if your cat is sick, it should be removed from the household. In addition, women who are pregnant or planning pregnancy soon should avoid eating raw or undercooked meat and should wash their hands and food preparation surfaces after handling such meats.