Newborns at risk for congenital toxoplasmosis, review of 16 years

Abstract

AIMS: To analyze the data on pregnancies with risk of congenital toxoplasmosis and to investigate the newborns’ outcome, in a level II hospital in Portugal. METHODS: A cross-sectional retrospective study included newborns at risk for congenital toxoplasmosis and their mothers, whose delivery occurred between January 2000 and December 2015. The inclusion criteria were mother with seroconversion to toxoplasmosis during pregnancy or first serum sample with positive specific IgM and IgG. The diagnosis of congenital toxoplasmosis was defined by positive specific IgM at birth and/or polymerase chain reaction positive in amniotic fluid and/or persistence of specific IgG up to 12 months of life. Congenital toxoplasmosis was defined as symptomatic when clinical findings were attributed to the disease. Chi-square or Fisher’s exact tests were used to test associations between variables, assuming statistical significance when p<0.05. RESULTS: There were 39,585 live births in the study period and 98 cases with risk of congenital toxoplasmosis were identified, of which 89 completed the follow-up. The prevalence of anti-T. gondii IgG in the pregnant women was 26% (95% confidence interval [CI] 24-27%). Twenty-two cases of congenital toxoplasmosis (5.6 per 10,000 live births, 95%CI 3.5-8.5 per 10,000) were confirmed. Of the 22 newborns, 18 (82%, 95%CI 61-93%) were symptomatic. The most frequent clinical findings were intracranial calcification (64%), hepatomegaly and / or elevation of transaminases (32%) and retinochoroiditis (14%). Cerebral lesions were more frequent when maternal infection was documented in the first and second trimester compared to the third trimester (p=0.018). In 31 cases (35%), the pregnant women were treated from the time of diagnosis until delivery with spiramycin, and no differences were found regarding the rate of vertical transmission or the appearance of clinical manifestations among the newborns of treated and non-treated mothers treated. CONCLUSIONS: The prevalence of congenital toxoplasmosis was higher than that reported in other European countries. The prevalence of intracranial calcifications was higher than that described in the literature, whereas retinochoroiditis and strabismus occurrence was lower. Brain lesions in newborns were more frequent in first- and second-trimester infections. There was no difference in the rate of vertical transmission and in the occurrence of clinical manifestations among newborns whose mothers received spiramycin during gestation and those whose mothers did not receive treatment.