Long-term follow-up of a series of 24 congenital CMV-infected babies with false negative amniocentesis.

BACKGROUND: Congenital CMV infection is the most common congenital infection worldwide and a major cause of neurological impairment and sensorineural hearing loss. Fetal CMV infection is confirmed by a positive PCR test in the amniotic fluid (amniocentesis performed after 18-20 weeks of gestation and at least 8 weeks after maternal infection). However, despite a negative antenatal CMV PCR result, some newborns can be tested positive at birth. Although not widely documented, the prognosis for these babies appears to be good.

OBJECTIVES: The aim of this study is to evaluate the long-term prognosis of fetuses with a false-negative AFS for cCMV, with a minimum follow-up period of 6 years.

STUDY DESIGN: This is a retrospective cohort study of false-negative amniocentesis reported at the CUB-Hôpital Erasme and Hôpital CHIREC in Brussels between 1985 and 2017.

RESULTS: Of the 712 negative CMV PCR amniocenteses, 24 had a CMV PCR positive at birth. The false negative rate was 8.6 %. Of the 24 cases, 9 primary maternal infections occurred in the first trimester, 14 in the second trimester and 1 in the third trimester. Among the 24 children, 2 had symptoms at birth (hyperbilirubinemia and left paraventricular cysts), but all had normal follow-up (minimum 4 years, mean 16,6 years).

DISCUSSION: Only 2 cases could be explained by early amniocentesis. Among the others, the false-negative results could be attributed to a low viral load, a delayed infection or, less likely, to a sample degradation.

CONCLUSION: Despite the false-negative results, all 24 children had a normal long-term follow-up.