Which diagnostic technique is used to assess for Toxoplasmosis in cases of fetal exposure?

Amniocentesis with PCR is a diagnostic technique that is particularly effective in assessing for Toxoplasmosis in cases of fetal exposure. This method involves extracting amniotic fluid from the uterus, which can then be analyzed for the presence of Toxoplasma gondii DNA using polymerase chain reaction (PCR). This technique is sensitive and specific, allowing for the detection of the parasite at a stage where other methods may not be effective.

In contrast, ultrasound can identify certain physical anomalies or signs of congenital infection but does not directly test for the presence of the Toxoplasma organism. Postnatal blood screening may be helpful once the infant is born but does not address in utero exposure. X-ray imaging is generally not used for diagnosing Toxoplasmosis as it does not provide relevant information about the infection. Thus, amniocentesis with PCR stands out as the most direct and reliable method for evaluating fetal exposure to Toxoplasmosis.