Antenatal toxoplasmosis screening and treatment in Northern Italy: update on the clinical effectiveness.

Background: Antenatal universal screening for toxoplasmosis is recommended in most affluent countries worldwide. Despite evidence is not robust, detected cases are typically treated during pregnancy. Affected newborns are also treated to temper clinical consequences. However, this established mode of management warrants careful and continuous re-evaluation. The epidemiology of the infection is changing and there is the need to monitor the clinical scenario.

Methods: This is an observational retrospective study conducted at a referral hospital in Northern Italy. Every woman referred from January 2011 to December 2021 for suspected toxoplasmosis in pregnancy was eligible. All women were managed according to a local standardized protocol. Clinical and laboratory findings were obtained from patients' charts.

Results: Out of 347 women referred, 191 (55%) were discharged as false positive at initial assessment. We identified 141 women with suspected infection and 15 with confirmed infection. The number of women treated with antibiotics was 136 (96%) and 15 (100%), respectively. A total of 118 amniocenteses were performed, all of which were negative. There were two spontaneous miscarriages and five therapeutic terminations of pregnancy (of whom four were consequent to parental concerns related to the toxoplasmic infection), all among suspected cases. Vertical transmission occurred in a single case, a patient with confirmed infection diagnosed by seroconversion at 28 weeks' gestation. The course of this pregnancy was uneventful, and the infant is healthy at 7 years follow-up. Overall, the incidence of vertical transmission was 7% (95% CI: 1-30%) in confirmed cases and 0% (95% CI: 0-0.2%) in suspected cases.

Conclusions: The current policy of universal screening and prompt management of toxoplasmosis infection is efficient. However, undue invasive procedures and terminations of pregnancy could occur. Future studies are warranted to improve clinical management.