Fetal blood sampling in fetuses with congenital cytomegalovirus and normal prenatal imaging

TO THE EDITORS: We read with interest the article by Pomar et al,1 which evaluated the contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus (cCMV) infections. Combining the results of fetal blood sampling (thrombocytes 120,000/mL, viremia <5 log10/mL, and b2 microglobulin <12 mg/L) with the absence of severe brain ab- normalities in cytomegalovirus (CMV)-infected fetuses improves the negative predictive value for moderate to severe symptomatic infection up to 100%. However, fetal blood sampling is an invasive procedure with potential complications, including bleeding from the puncture site, fetal bradycardia, and pregnancy loss. In the absence of mild cerebral or extracerebral signs of infection, we are wondering if it’s worth taking the risk. How many cases with normal prenatal imaging throughout the pregnancy have devel- oped moderate to severe symptomatic infection during the postnatal follow-up? Few studies focused on the outcomes of fe- tuses with cCMV following maternal primary infection during the rst trimester with normal prenatal imaging.2,3 They report that hearing loss and mild development delay can occur, but the risk of moderate to severe sequelae seems to be extremely low. How should the presence or absence of abnormal results from fetal blood sampling change our counseling in these cases? In our experience, in the presence of normal ultrasound and/or magnetic resonance imaging ndings, the long-term sequelae are mainly limited to sensorineural hearing loss. We acknowledge that counseling for CMV is still challenging, but we believe that the risks associated with fetal blood sampling in cases with normal prenatal imaging are not justi ed.