Chickenpox in pregnancy

By Dr. Tarek RabieiPGY 3 -OBGYN

Supervised by Dr Moone Consultant – OBGYN

  varicella zoster virus is one of eight herpes viruses. Varicella infection in children is generally a mild disease.in adults: it can be more sever During pregnancy: mother :varicella pneumoniaFetus :congenital anomalies

Introduction

Varicella zoster virus : varicella (chickenpox) herpes zoster (shingles)

diseases

 Primary VZV infection : Age :less than 2 %

mortality increases with age 25% early gestational period (weeks 8 to 20), Maternal varicella during pregnancy is also

associated with the subsequent development of herpes zoster during infancy

Herpes zoster — Endogenous reactivation of latent VZV not associated with risk of congenital anomalies

Incidence

TRANSMISSION — is higher with exposure to varicella compared with zoster.

Persons are not considered infectious once lesions have crusted over.

Duration of infection start 2-3 days before fever till lesion has crusted over

Mode of transmission :a) dropletb) direct contact with vesicular fluidc) very rare airborne virus

Mother to infant : prenatal postnatal intrauterine .

Transmission

Congenital varicella : Less than 2 % of women who have acquired varicella infection during the first 20 weeks of pregnancy has baby with congenital varicella syndrome

Incidence

Uncomplicated varicella — rash, fever crops of vesicles. New vesicle formation generally stops within four daysmacules then pustule followed by crusted papules. Most lesions have fully crusted by day six. Crusts falls one to two weeks . Complicated infection —more common in adults Most common complication in pregnancy varicella

pneumonia meningitis, encephalitis, cerebellar ataxia, pneumonia, glomerulonephritis, myocarditis, ocular disease, adrenal insufficiency, Secondary bacterial and death  

CLINICAL FEATURES OF MATERNAL VZV INFECTION

Cutaneous scars Neurological Ocular abnormalities Limb abnormalities Low birth weight

Congenital varicella syndrome is associated with a mortality 30% in the first few months of life,15% risk herpes zoster in the first four years of life

FETAL EFFECTS OF VZV INFECTION

The diagnosis clinical. If there is doubt, VZV viral DNA by PCR

testing of skin scrapings from the base of the vesicle, vesicular fluid or through the detection of VZV antigen by immunofluorescence

DIAGNOSISMaternal varicella 

Prenatal diagnosis :   PCR fetal blood or amniotic fluid usually between 17 –21 weeks + ultrasonography after 5 weeks from maternal infection

DIAGNOSISCongenital varicella syndrome

Postnatal diagnosis — The diagnosis of congenital varicella syndrome requires the following criteria : ◦ History ◦ fetal abnormalities consistent with congenital

varicella syndrome ◦ Evidence of intrauterine VZV infection :detection of VZV DNA in the newbornIgM antibodies in cord bloodVZV IgG beyond seven months of age clinical zoster infection during early infancy.

Canadian guide lines In the case of a exposure to varicella in a pregnant woman with unknown immune status serum testing should be performed. If the serum results are negative or unavailable within 96 hours from exposure, varicella zoster immunoglobulin should be administered.

Exposure and IG

Uncomplicated varicella infection  the efficacy of acyclovir within 72 hours of

symptom onset . faster healing of skin lesions and a shorter duration of fever, if initiated within 24 hours of symptom onset .

However acyclovir therapy (20 mg/kg PO four times daily for five days) for all pregnant women with uncomplicated varicella

Treatment of varicella infection

Varicella pneumonia —  medical emergency; the mortality rate n the era prior to antiviral therapy approximated 36 to 40 percent in case series reports

It is recommended intravenous acyclovir  (10 mg/kg every eight hours).

Varicella zoster virus has 2 form of disease chicken pox and herpes

Incidence in adult is very low but very sever Transmission droplet , vesicle fluid ,airborne Most severe complication pneumonia Early during pregnancy can cause congenital

varicella syndrome Antiviral treatment benefit over weight the risk On exposure for sero negative mother IG is

recommended

Summary and recommendation

Thank you.