Pregnancy complications, infectious Archives - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to establish the frequency of acute toxoplasmosis in pregnant women, vertical transmission rate and the perinatal results of the infected fetuses and also to evaluate the relationship between the most used maternal-fetal diagnostic tests for toxoplasmosis during pregnancy and the relationship between age and acute toxoplasmosis infection during pregnancy. METHODS: longitudinal prospective study of 32,512 pregnant women attended by The Pregnancy Protection Program of the State of Mato Grosso do Sul - Brazil, from November 2002 to October 2003. ELISA (IgG and IgM) and IgG avidity test were performed for maternal diagnosis and amniotic fluid PCR for fetal investigation of the infection. The relationship between data was analyzed statistically by the chi2 or two-sided Fisher's exact test in contingency tables. RESULTS: a 0.42% frequency of acute Toxoplasma gondii infection among pregnant population was found, where 92% were previously exposed and 8% were susceptible. Among IgM-positive pregnant women, the age ranged from 14 to 39 years, with a mean of 23±5.9 years. There was no statistically significant relationship between age and maternal acute T. gondii infection (p=0.73). The vertical transmission rate was 3.9%. A statistically significant relationship was shown (p=0.001) between a lower avidity IgG test (<30%) and the presence of fetal infection and a higher IgG avidity test (>60%) and the absence of fetal infection. There was a statistically significant association (p=0.001) between fetal infection (amniotic fluid PCR) and neonatal infection. CONCLUSIONS: maternal acute toxoplasmosis frequency was lower than the Brazilian national parameters, whereas vertical transmission rate did not differ from the rates found in other studies. The IgG avidity test, when associated with gestational age and the examination date, was useful to evaluate the therapeutical options and to consider the risk of vertical transmission when performed before 12 weeks. Positive PCR in amniotic fluid showed a positive relationship with the worst neonatal prognosis, being a specific method in diagnosing intrauterine fetal infection.