Management and Outcome of Pregnancies with Parvovirus B19 Infection over Seven Years in a Tertiary Fetal Medicine Unit

Abstract

Objectives: To determine rates of fetal anaemia and pregnancy outcome in susceptible pregnant women infected with human parvovirus B19 infection in a tertiary fetal medicine department over a 7-year period. Additional features enabling identification of fetuses that progress to severe anaemia were also investigated. Methods: Forty-seven susceptible, pregnant women with confirmed parvovirus infection referred to a regional fetal medicine unit, over a 7-year period (1999–2006), were identified. Where possible maternal serum AFP measurements were obtained from second-trimester serum screening and the presence or absence of echogenic bowel noted. Results: Of the 47 cases, one was excluded. Of the remaining 46 cases, 34 (74%) showed no signs of fetal anaemia and delivered at term. The remaining 12 (26%) showed signs of fetal anaemia. Eight of the 12 developed hydrops and underwent fetal blood sampling and transfusion (median pretransfusion Hb 3.6 g/dl). Seven of the 8 transfused fetuses were thrombocytopenic with a platelet count <150 × 10⁹/l, with 2 fetuses having platelet counts <50 × 10⁹/l. The median gestation age at transfusion was 22 weeks (range 18–27 weeks). The median number of weeks between seroconversion and transfusion was 6 (range 3–12). The signs of anaemia resolved after one transfusion in 5 of the 8 transfused fetuses and they subsequently delivered at term. There were 2 fetal deaths during or shortly after transfusion and one neonatal death following delivery at 28 weeks gestation due to severe pre-eclampsia, 5 days after successful transfusion. Conclusions: Following parvovirus seroconversion, the incidence of significant fetal anaemia requiring transfusion was 17%. Seroconversion after 21 weeks did not result in severe fetal anaemia. Significant anaemia requiring intervention did not occur 12 weeks after maternal seroconversion. We did not demonstrate a correlation with either maternal serum AFP or the presence of fetal echogenic bowel and the development of severe fetal anaemia. Because of the association between fetal anaemia and severe thrombocytopenia, it may be prudent to have compatible platelets available at the time of fetal blood sampling.

Therapeutic management of fetal anemia: review of standard practice and alternative treatment options

“…Most cases are detected upon the fi nding of fetal hydrops in the ultrasound assessment, although there are also pregnant women referred due to seroconversion for parvovirus B19. Close ultrasonographic surveillance on a weekly basis for 10 -12 weeks after the estimated time of exposure for signs of fetal anemia, heart failure, and hydrops and Doppler screening (Doppler examination of the MCA) after initial seroconversion can identify the subgroup with fetal anemia that needs to be transfused [71] . Delle Chiaie et al observed that a cut-off value of 1.29 MoM for MCA-PSV could predict any degree of fetal anemia induced by parvovirus infection with sensitivity and specifi city of 100 % [17] .…”

Early Intrauterine Transfusion in Fetuses with Severe Anemia Caused by Parvovirus B19 Infection

“…In a recent review [8], perinatal survival after IUT was 66.7-72.2% in parvovirus B19-infected fetuses versus 80.0-93.5% in cases of red blood cell alloimmunization. Other series comprising transfusions in parvovirus B19-induced anemia found survival rates between 33 and 100% (cumulative percentage 78%) [1,6,11,12,[23][24][25][26][27][28][29]. GA varied between studies, but cases before 20 weeks of gestation were rarely included.…”

“…In contrast to a number of studies reporting the outcome of IUTs in red blood cell alloimmunization [8][9][10], data on intrauterine treatment of parvovirus B19-related anemia are limited [1,6,11,12]. While the majority of transfusions in red blood cell alloimmunization are performed beyond 20 weeks, parvovirus B19 often affects fetuses in the early second trimester.…”

“…The small singlestranded round DNA virus binds to the P antigen, which is present on the surface of erythrocytes, erythroblasts, megakaryocytes, endothelial cells, placental cells, and fetal liver and heart cells. It destroys the erythroid progenitor cells, produces aplastic anemia, and can cause viral myocarditis [1,2]. Moreover, it can affect progenitor cells of other cell systems and lead to distinct thrombocytopenia.…”

Parvovirus B19 Infections in Pregnant Women and Neonates: Review

“…Parvovirus B19 infection called "erythema infectiosum" usually causes a febrile illness but may be a problem especially in patients with chronic hemolytic anemia and pregnant women. 7,8 Transmission is mainly through respiratory droplets but possible by transfusion of infected blood products. 9 In pregnant women the virus passes through placenta.…”