[Varicella in pregnancy].

Chickenpox rarely occurs during pregnancy but affected patients risk not only varicella pneumonia but also fetal contamination with potentially malformative effects or severe neonatal infection depending on whether the infection occurs early or late during pregnancy. More than 15% of the affected women have detectable lesions on the chest X-ray. Respiratory distress is the main risk with mortality reaching nearly 20%. Fetal contamination occurs via transplacental transmission. Fetal malformations are observed in less than 5% of the cases when fetal infection occurs early (before the end of the fifth month) but are generally quite severe. The mechanism is apparently fetal zona a few weeks after initial infection. Antenatal diagnosis is generally obtained on the basis of sonographic findings, and identification of viral genome using polymerase chain reaction on cordocentesis or amniotic fluid biopsy samples. Screening attempts to identify fetal anomalies and evaluate fetal prognosis. Induced abortion should be discussed in cases where both fetal malformation and fetal infection are confirmed. After five months, the risk of malformation appears to be much lower. It is known however that fetal varicella can be observed if the maternal infection occurs just before delivery. The most severe forms are seen when the maternal eruption occurs during the 4 days prior to delivery. Neonatal mortality in these cases reaches 20%. Unlike varicella, there is apparently little or no risk either for the mother or for the child in case of zona during pregnancy.