A woman develops chickenpox at a period of gestation of 8 weeks.What is the best method to exclude foetal varicella syndrome?

Ans. is b, i.e. Perform an ultrasound scan at 20 weeks.A detailed ultrasound examination carried out 5 weeks after infection, or at 16-20 weeks is the best method to exclude fetal varicella syndrome.Amniocentesis is not routinely advised because the risk of congenital varicella syndrome is low, even when amniotic fluid is positive for VZV DNA because amniocentesis has a strong negative productive value than a positive predictive valve.