UNASSIGNED: The parasite @entity3204 might harm the fetus if a @entity1 is infected during pregnancy. IgG seroconversion and significant increase in IgG antibody amount in pregnancy indicates @entity281 . Presence of @entity3204 immunoglobulin M (IgM), immunoglobulin G (IgG) and low IgG avidity in a single serum sample indicates possible @entity281 , but positive @entity3204 IgM and low IgG avidity may persist for months and even years. We aimed to evaluate avidity development during pregnancy in a retrospective study. Serial blood samples from 176 pregnant @entity1 admitted to Oslo University Hospital 1993-2013 for amniocentesis because of suspected @entity3204 infection were included. Data were obtained from journals and laboratory records. The avidity method used was based on Platelia Toxo IgG assay. Mean maternal age at first serology was 29.9 years (SD 5.2, range 18-42). In 37 (21%) @entity1 only the avidity increased from low to high in < 3 months. In 139 (79%) the IgG avidity remained below the high threshold >=  3 months and within this group 74 (42%) @entity1 had stable low IgG avidity during the observation period. Median gestational age at first test was 10.6 weeks (range 4.6-28.7). @entity2241 was detected in four @entity1 , but none among @entity1 whose mother had stable low IgG avidity. The first antenatal @entity3204 serology should ideally be collected in early pregnancy and if stable values of @entity3204 IgM and low IgG-avidity are detected in a second sample after three to four weeks, the need for amniocentesis can be questioned.

Persistent Low XXXX IgG Avidity Is Common in Pregnancy: Experience from Antenatal Testing in Norway.

@entity1 :: ('9606', 'Species') :: ['women', 'children', 'woman'] @entity281 :: ('MESH:D007239', 'Disease') :: ['maternal infection'] @entity2241 :: ('MESH:D005315', 'Disease') :: ['Fetal infection'] @entity3204 :: ('5811', 'Species') :: ['Toxoplasma gondii', 'toxoplasma']
@entity3204 :: (5811,Species) :: ['Toxoplasma']
