Maternal serum alpha-fetoprotein--a marker of fetal aplastic crisis during intrauterine human parvovirus infection.

In 2 cases of hydrops fetalis and intrauterine death associated with human parvovirus B19 infection that produced very few symptoms during the second trimester of pregnancy, maternal serum alpha-fetoprotein levels were raised, before the ultrasonic detection of hydropic features. Fetal blood sampling in 1 case revealed the features of aplastic crisis. A retrospective study of 3 other affected and 11 unaffected cases of B19 infection during pregnancy showed a correlation between raised maternal serum alpha-fetoprotein level and poor prognosis for the affected pregnancies, with the subsequent development of hydrops fetalis.