A 26 years old female, attending our antenatal outpatients section, was found positive for toxoplasmosis, during the 13th week of pregnancy. She reported no other maternal medical conditions and the infection was confirmed during routine tests. This was her second pregnancy and she had a history of previous cesarean delivery. Her history was negative although she reported that she was taking care of a cat recently. All the other antenatal tests were normal.
The patient was admitted to our center. Physical examination during admission was normal. Her initial serologic tests were: IgG 249 IU/ml (normal range 0-6 IU/ml), IgG avidity 0.010% (normal range 0-0.2%), IgM >160 IU/ml (normal range 0-10 IU/ml). Tests were repeated and additionally IgA was measured. The new laboratory results were: IgG > 400 IU/ml, IgG avidity 4.4%, IgM 63 IU/ml and IgA 13 IU/ml. The finding of positive IgA and the gradual increase of IgG avidity confirmed the presence of a recent infection that happened during the last six weeks. In view of these findings an amniocentesis was conducted at 15 weeks in order to examine whether the fetus was affected. PCR-DNA test of the amniotic fluid was negative. Although there was no evidence of vertical transmission the infection was confirmed and the patient received treatment with spiramycin 1gr three times a day (t.i.d.).
Serologic tests were repeated during the 20th week: IgG 440 IU/ml, IgG avidity 23%, IgM 51 IU/ml and IgA negative. At this point a new amniocentesis was conducted and this time PCR-DNA test of the amniotic fluid was positive for the parasite. At 23 weeks of gestation a cordocentesis was operated and serologic tests results were: IgG 310 IU/ml, IgG avidity (considered to be of maternal origin since fetus cannot produce IgG) 16%, IgM and IgA negative. Fortunately fetal blood PCR did not reveal infection of the fetus. Serologic tests at 35 weeks of gestation were: IgG 84 IU/ml, IgM 17 IU/ml and IgA negative. Ultrasound examinations were performed monthly and no fetal abnormality was detected at any time point.
The patient suffered preterm contractions since the 35th week of pregnancy and finally was subjected to cesarean delivery at 36 weeks of pregnancy. The newborn was a healthy girl with a birth weight of 2880 gr. Serological tests of the child (blood sampling from umbilical cord) were: IgG 74 IU/ml, IgG avidity (considered of maternal origin because newborn also cannot produce IgG) 64%, IgM and IgA negative. Tests were repeated one month later with the same results.