Varicella / Chicken Pox
        Main and The Obgyn Clinic of Hvidovre (danish)
        Most adults have had varicella zoster (VZ).
        The incubation period 10-21 days.
        Highly infectious (about 90%) 48 hours before the rash and last until the vesicles crust is over.
        Very contagious, the whole department infected (face to face 5 minutes or indoor contact more than one hour).
        Previous infection can be confirmed by measuring VZV antibodies.
        Zoster may occur months to years after primary varicella infection.

        Maternal:
          Varicella is most often uncomplicated, but can be more severe in adults and particularly in immunosuppresed women and pregnant women.
          Pneumonia occurs in up to 10%, with mortality up to 45% in the pre-antiviral era. The mortality today is less than 1%.
          Mechanical ventilations can be required with up to 6% mortality. Other complications include encephalitis, generalized spread to internal organs, hepatitis, arthritis, pericarditis, glomerulonephritis, Reye's Syndrome and hemorrhagic varicella.

        Herpes Zoster: No risk for the foetus.

        Congenital Varicella:
          From 0-12 weeks, there is a 0.4% risk for congenital varicella and from 10-20 weeks, the symptoms of congenital varicelle are:
          Low birthweight, neurological abnormalities (microcephaly, cortical atrophy, mental retardation and dysfunctional bowel and bladder sphincters.
          Eye defects (microphthalmia, chorioretinitis, cataracts)
          Hypoplasia of the limbs
          Skin scarring in a dermatomoid distribution
        If the mother is infected by Varicella 5 days before and 4 days after birth then there is risk for serious infection in the child. However, if the mother get VZIG only slight symptoms. Often only slight symptoms 6-21 days before and 1-2 weeks after birth. Very preterm babies are at high risk for severe symptoms.

        Prenatal diagnosis:
          Primary ultrasound after 5 weeks.
          Amniocentesis with PCR for viral DNA PCR, otherwise with detection of IgM antibodies in fetal blood. However, both these tests may give false negative results.VZV antibodies of limited valu

        Varicella Infection of the Newborn:
        In the first 28 weeks of pregnancy and within 3 weeks of delivery, mother should receive 1,000 mg VZIG immediately after exposure if known or found to be IgG negative. If the mother present with symptoms the value of VZIG is uncertain and the patient should receive antiviral treatment in the form of acyclovir or valcyclovir.

        Up to 50% infections are infected 1 to 4 weeks before delivery. Is fatal in 20-30% of infants if maternal infection occurs 5 days before the delivery and up to 2 days postpartum, but severe infection up to one month has been seen.

        The infant is protected by maternal antibodies at least one month after delivery. Newborns should not be exposed to VZ if mother have not had the disease.

        Management:
          In case of exposition in the vulnerable period VZIG to the infant and mother as well as Acyclovir. Isolation from all other pregnant women and neonates. If delivery occurs within 5 days of infection or mother develops VZ within 2 days after delivery then the neonate should be given VZIG and Acyclovir as soon as possible. Anti-viral therapy should be precribed for chickenpox if they present within 24 hours of the rash and if they are more than 20 weeks gestation.

        Prophylactic:
          Pregnant women should not be exposed to Varicella before 20 weeks of gestation. Women with Varicella should not be admitted to labor ward. The room is infected at least 1 hour.

        Vacination:
          Avoid pregnancy in 3 months.

        References:
        (1) Chickenpox in pregnancy. Green-top Guideline Nor. 13, September 2007

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