An ongoing 5-year prospective study of the outcome of contact with varicella-zoster virus (VZV) and infection in pregnant women has made use of a standardized VZV enzyme-linked immunosorbent assay for the determination of immune status and as a guide for therapeutic management. Out of of a total of 778 such cases investigated to date in the Federal Republic of Germany, 93.1% have been shown to be VZV immune, whereas 6.9% were seronegative and, therefore, susceptible to infection. Those of the latter group who received zoster hyperimmunoglobulin (ZIG) between 24-96 hours after varicella contact remained symptom-free, while women receiving ZIG from the 3rd-10th day after contact developed a modified varicella. For the prevention of varicella, ZIG with known titres should be administered at doses of 0.2-0.4 ml/kg. It is also recommended for the newborn when maternal infection occurs within 4 days before until 2-4 days after delivery. The prevention and attenuation of varicella in pregnancy is justified since the outcomes may include spontaneous abortion in early pregnancy, the congenital varicella syndrome, and severe neonatal disease with a rather high mortality around term.