Prenatal diagnosis of infectious diseases has been shown to be indispensable to confirm or exclude in utero infections due to cytomegalovirus, rubella, toxoplasmosis, varicella, parvovirus and herpes simplex, and a multidisciplinary approach is needed. Our report is on data obtained from 236 pregnant women at risk for the above-mentioned conditions. The specific IgM test suggested seroconversion in only 198 of these patients and 162 of them requested prenatal diagnoses by means of fetal blood sampling or amniocentesis, or both. The results are encouraging but more work is required to optimize our diagnostic approach, i.e., monoclonal antibodies and DNA probes with direct identification by means of choronic villi sampling, which we use for prenatal diagnoses of hemoglobinopathy (DNA-genetic).