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MS WordPerinatologist Corner - C.E.U/C.M.E. Modules
Varicella in Pregnancy
4. Diagnosis
Case scenario #2
IG is a 24 y/o G1P0 at 40 weeks gestation who works as an elementary school
teacher. She is seen for persistent Braxton-Hicks contractions and reports that
one of the children in her classroom was diagnosed with chicken pox today. She
doesn’t know if she ever had chicken pox as a child herself. She wonders if her
exposure to this child presents any danger to her about to be born baby.
Maternal infection may be more severe than the infection in children and up to
14% of pregnant women may develop varicella pneumonitis manifesting as
dyspnea, hemoptysis, pleurodynia, and hypoxia 2 to 6 days after the rash
appears. (McCarter-Spalding) The mortality of this complication used to be up to
40% but is closer to 3 to 15% with modern intensive care. Encephalitis,
manifested as progressive headache, seizures, or altered consciousness may
also result in death or neurologic deficits. Spontaneous abortion is not more
common after varicella infection. (Figure 2)
The diagnosis of varicella is usually made clinically. VZV may be cultured from
vesicular fluid, but this is a cumbersome process. Serologic tests may help
document acute infection in confusing cases or indicate immunity. IgM antibody
may be detected as soon as three days after VZV symptoms appear, and IgG
may be detected as early as seven days after varicella symptoms. Multiple
antibody detection assays are available including fluorescent anti-membrane
antibody (FAMA), latex agglutination (LA), enzyme-linked immunosorbent assay
(ELISA), and complement fixation tests.
Prenatal diagnosis of fetal varicella infection is possible. Ultrasonography can
detect limb abnormalities in affected fetuses. In other studies, fetal blood has
been obtained via percutaneous blood sampling for VZV antibody or DNA on
blood or amniotic fluid. Although serologic methods can identify VZV infectiion
early in fetal development, they cannot predict sequelae from VZV infection.
