[Prenatal diagnosis of fetal varicella in the second trimester of pregnancy].

The first case of prenatal diagnosis of congenital varicella by amniotic fluid viral culture and PCR is reported. Chickenpox is a benign disease in children, but it can lead to severe complications in the adult, especially in the pregnant woman. Five percent of women in childbearing age are not immunised, and the incidence of gestational chickenpox is between 1 and 7 per 10,000. The consequences of this primary infection during pregnancy can be severe for the mother, because of the risk of serious varicella pneumonia, and for the fetus. The fetal infection depends on the gestational age at which the maternal infection occurs. The 2% evaluated risk of fetopathy is maximal between the 7th and 20th week of amenorrhoea. The reported congenital abnormalities are essentially cutaneous, neurological, ophthalmological and musculo-squeletal lesions. A prenatal diagnosis can be suggested: the revelation of defects by ultrasound scan confirms the fetal affection, and can justify pregnancy termination; on the other hand, amniocentesis and cordocentesis are not totally safe, and cannot always assert the fetal contamination or its level of affection. From the therapeutical point of view, prevention with polyvalent gamma-globulin is prescribed to non-immunised pregnant women who have been in contact with the virus. On the opposite, in case of contracted chickenpox, the treatment of the mother with an association of polyvalent gamma-globulin and acyclovir is still controversial since, although probably effective, it may not be safe for the fetus. The solution may reside in the vaccination, soon available, of non-immunised women in childbearing age.