Refining the prognosis of fetuses infected with Cytomegalovirus in the first trimester of pregnancy by serial prenatal assessment: a single-centre retrospective study.

Objective: To define the predictive value (PV) of known prognostic factors of fetal infection with Cytomegalovirus following maternal primary infection <14 weeks of gestation, at different time points of pregnancy: the end of the second trimester; following prenatal magnetic resonance imaging (MRI) at 32 weeks of gestation; and using all ultrasound scans performed in the third trimester (US3rdT).

Design: A retrospective study.

Setting: Reference fetal medicine unit.

Population: Sixty-two fetuses infected <14 weeks of gestation.

Methods: We defined second-trimester assessment (STA) as the combination of ultrasound findings <28 weeks of gestation and fetal platelet count at cordocentesis. Three groups were defined: normal, extracerebral, and cerebral STA.

Main Outcome Measures: For each group, the PV of STA alone, STA + MRI, and STA + US3rdT were assessed retrospectively. Outcome at birth and at follow-up were reported.

Results: The STA was normal, and with extracerebral and cerebral features, in 43.5, 42.0, and 14.5%, respectively. The negative PV of normal STA and MRI for moderate to severe sequelae was 100%. The residual risk was unilateral hearing loss in 16.7% of cases. Of pregnancies with cerebral STA, 44% were terminated. Following extracerebral STA, 48% of neonates were symptomatic and 30% had moderate to severe sequelae. In those cases, the positive and negative PV of MRI for sequelae were 33 and 73%, respectively. STA + US3rdT had a lower negative PV than MRI for symptoms at birth and for moderate to severe sequelae. Any false-positive findings at MRI were mostly the result of hypersignals of white matter.

Conclusions: Serial assessment in the second and third trimesters by ultrasound and MRI is necessary to predict the risk of sequelae occurring in 35% of pregnancies following fetal infection in the first trimester of pregnancy.

Tweetable Abstract: Serial ultrasound prognostic assessment following fetal CMV infection in the 1st trimester is improved by MRI at 32 weeks.