VZV can cross the placenta in the last stages of pregnancy and infect the fetus. Neonatal chickenpox can range from a mild disseminated infection to a fatal one. If the mother has rash a week before birth, the fetus may be immune to infection. Transmission – transplacental – rare, perinatal 25%, when the mother presents acute infection within the first 10 days of birth, with mortality = 30% in perinatal infection. Clinically, congenital varicella – is rare – occurs when maternal infection takes place in the first trimester of pregnancy and is associated with CNS abnormalities and ocular anomalies.
In general, postnatal Chickenpox is a mild, rarely reported form.
Pregnant women likely to have had contact with VZV must receive anti-VZV immunoglobulins.
Immunoglobulins should also be administered to children whose mothers make chickenpox in the last week of gestation or in the first two weeks of childbed.
Earlier studies of complicated varicella pregnancies have clearly shown the risk of maternal-fetal transmission. Thus from 43 pregnancies in which the mother was infected with VZV were born 7 children with congenital impairment due to VZV.
(Paryani SG, Arvin AM. Intrauterine infection with varicella-zoster virus after maternal varicella. New England Journal of Medicine. 1986 Jun 12; 314 (24): 1542-6).
More extensive studies on a lot of 1373 women who had chickenpox and 366 herpes zoster during pregnancy were performed and 9 cases of congenital varicella were revealed after 36 weeks of gestation, all occurring after varicella contracted in the first 20 for weeks. The biggest risk was between the 13-20 weeks. None of the children who came from mothers who had herpes zoster had any signs of intrauterine infection.
(Enders G, Bolley i, Miller E, Cradock-Watson J, Ridehalgh M. Consequences of Varicella and herpes zoster in pregnancy: prospective study of 1739 cases. The Lancet. 1994 Jun 18; 343 (8912): 1548-51).
More recently there were analyzed 52 infants whose mothers contracted the infection during pregnancy and it was observed that 27 presented congenital malformations, and 25 developed early herpes zoster during the postnatal period. In the case of those who had congenital malformations, mothers had contracted the infection during the first 20 weeks of pregnancy, while in those who developed herpes zoster, mothers had contracted the infection after 21 weeks.
(Kumar RM, Frossad PM, Hughes PF. Seroprevalence and mother-to-infant transmission of hepatitis C in asymptomatic Egyptian women. European Journal of Obstetrics & Gynecology and Reproductive biology. 1997 DEC 1; 75 (2): 177-82).
About Corneliu Zaharia
