Anticytomegalovirus IgG avidity in pregnancy: a 2-year prospective study.
OBJECTIVE
To analyze the practical use of the anticytomegalovirus IgG avidity and its impact on the follow-up of pregnancy. To evaluate the performance of IgG avidity to exclude the risk of congenital infection.


METHODS
409 IgM-positive women without a documented seroconversion were prospectively followed. Data concerning the follow-up of the pregnancies were collected (amniotic fluid puncture and samples from the offspring). These observations were compared to those of 76 seroconversions during the same period.


RESULTS
High avidity excluding a primary infection within the past 3 months was observed in 270 women. As the gestational age was less than 3 months for 121 women, exclusion of a primary infection was achieved in 30% of the cases. The rate of amniotic fluid puncture was influenced by the serological result: high avidity (9%), low avidity (42%) and seroconversion (65%).


CONCLUSIONS
A high avidity index during the first trimester of pregnancy could reasonably be considered as a good indicator of past infection and invasive prenatal diagnosis is not necessary. Nearly 70% of the IgM-positive women could be reassured if the first serology was systematically performed before 12 weeks of gestation.
Bodéus
M
M
Department of Microbiology, Unit of Virology, Université Catholique de Louvain, Brussels, Belgium. Bodeus@mblg.ucl.ac.be
Van Ranst
M
M
Bernard
P
P
Hubinont
C
C
Goubau
P
P
D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D000915:Antibody Affinity; D003587:Cytomegalovirus / Q000276:immunology / Q000302:isolation & purification*; D003586:Cytomegalovirus Infections / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000821:virology*; D011256:Pregnancy Outcome; D011446:Prospective Studies
D000914:Antibodies, Viral; D007074:Immunoglobulin G