We describe a 28-year-old woman with primary Sjögren's syndrome who had a miscarriage in the 10th week of gestation in December 1993. In her second pregnancy plasma hyperviscosity and high antibody reactivities to 52/60 kD Ro(SS-A) and La(SS-B) represented elevated risk factors for abortion and fetal congenital heart block. Therefore, we performed plasmapheresis and administered dexamethason. At the end of 37th week of gestation a healthy boy was born by caesarean operation. Interestingly, antibody levels to the anti-Ro(SS-A)/La(SS-B) complex showed an increase during both pregnancies with a decline after the abortion as well as the partus. The combined therapy led to a decrease in both the autoantibody reactivities to 52 kD Ro(SS-A) and La(SS-B) and the plasmaviscosity. Plasmapheresis and dexamethason are safe treatment modalities in identified high risk pregnancies for the birth of a child with CHB.