Investigation and management of Toxoplasma gondii infection in pregnancy and infancy： a prospective study

Aim： Toxoplasma gondii infection during pregnancy poses a serious risk to the fetus, therefore timely and accurate diagnosis is essential. The aim of this study was to estimate the frequency of congenital infection via evaluating mother＇s immunological status and the possibility to improving the diagnostic and therapeutic approaches. Methods： Eighty five mothers with Toxoplasma seroconversion and their offspring were enrolled （among them, 2 spontaneous abortions were documented in the first trimester）. Prenatal PCR diagnosis was carried out on 50 patients （60%）, with 7 positive cases （14%）. Morphological ultrasound scanning revealed anomalies in one fetus. Long-term follow-up included general physical examinations, serological status tested using Western blot, neuro-radiological, ophthalmologic and neurologic examinations, psychological and developmental tests, visual evoked potential tests and audiology tests, as well as anti-Toxoplasma treatment regimes. Results： Fourteen （17%） of the infants were infected at one-year serological follow-up. Chi-square for linear trend of vertical transmission from the first to the third trimester was significant （P=0.009）. Western blot analysis showed IgM and IgA in half of the infected infants. In 69 uninfected infants, anti-Toxoplasma IgG immunoblot analysis excluded infection within the 3 months in 18 infants （26%） and in the others within 6 months of life. The most relevant instrumental findings are described. Conclusion： Western blot analysis may help to evaluate infection within the 6 months of life. The accuracy of ultrasound imaging to determine the brain damage in the fetus and newborns is doubtful, and should be combined with MR imaging. Multistep approaches can improve the timing of postnatal follow-up.