Management of Pregnant Women with Positive IgG for CMV and Rubella

Understanding the Serologic Results

The presence of IgG antibodies against CMV and rubella indicates past infection and established immunity, suggesting the patient is protected against primary infection during this pregnancy, according to the American College of Obstetricians and Gynecologists 1, 2
IgG positivity for both CMV and rubella indicates prior exposure and established immunity to these infections, as stated by the American College of Obstetricians and Gynecologists 1, 2
The presence of IgG antibodies alone, without IgM antibodies, suggests past infection rather than acute or recent infection, as reported by the American Journal of Obstetrics and Gynecology 3, 4
Laboratory confirmation of rubella immunity through IgG antibody is the only reliable evidence of protection against rubella infection, according to the American College of Obstetricians and Gynecologists 2

With IgG-positive and presumed IgM-negative results, there is no increased risk of congenital CMV or congenital rubella syndrome in the current pregnancy, as stated by the American College of Obstetricians and Gynecologists 1, 2
No amniocentesis is indicated, as this would only be recommended if primary CMV infection were suspected, according to the American Journal of Obstetrics and Gynecology 3
No additional serologic testing for CMV or rubella is needed unless clinical suspicion for acute infection develops, as reported by the American Journal of Obstetrics and Gynecology 3, 4

If ultrasound findings suggestive of congenital infection appear, then IgM testing and IgG avidity testing should be performed to rule out primary infection, according to the American Journal of Obstetrics and Gynecology 3, 4
Echogenic bowel on ultrasound has a 2-10% association with congenital CMV infection and would prompt CMV IgM and IgG avidity testing regardless of prior IgG status, as reported by the American Journal of Obstetrics and Gynecology 3, 4

Unlike seronegative women who require postpartum MMR vaccination, this patient with documented rubella IgG immunity does not need rubella vaccination, according to the American College of Obstetricians and Gynecologists 1, 2
Rubella vaccination is only indicated for women who remain seronegative postpartum to prevent congenital rubella syndrome in future pregnancies, as stated by the American College of Obstetricians and Gynecologists 1

Do not confuse IgG positivity with active infection—IgG alone indicates immunity, not disease, according to the American College of Obstetricians and Gynecologists 1, 2
If echogenic bowel or other concerning ultrasound findings develop later in pregnancy, do not rely on the initial IgG-positive result alone—obtain IgM and avidity testing to exclude primary infection occurring after the initial screening, as reported by the American Journal of Obstetrics and Gynecology 3, 4