In the serological screening of pregnant women for the prevention of congenital toxoplasmosis a positive test with low titre in the first trimester indicates almost with certainty a preconceptional infection. The probability that such a result derives from a very recent maternal infection leading to fetal infection is about 5 in 39,000. In view of the very high extra expenses involved and the unnecessary anxiety induced in many thousands of pregnant women and the sparse results the serological control of women showing positive tests with low or medium titre in the first trimester is not recommendable. There is no indication that preconceptional toxoplasma infection, especially the countless infections of longer standing with low titres, damage the fetus or lead to habitual abortion. Practically only H. Werner and his Berlin group, succeeded in isolating toxoplasma from abortion material of women not primarily infected during pregnancy but then in 20% of cases and in serologically-negative women also. The late importation of such opinions to Austria is deeply regrettable and should not be allowed to induce uncertainty in physicians and anxiety in our women. Accurate studies in very large numbers of preconceptionally-infected women did not reveal a single case of prenatal damage or congenital infection. Hence, the serological control of newborn infants of preconceptionally-infected women is not indicated. High titres (SF) detected during the first trimester indicate only a very low probability of damage to the fetus. Desmonts and Couvreur found not one infected infant amongst the offspring of 191 women with high titres at the beginning of pregnancy.