OC19.01: Congenital cytomegalovirus infection following maternal infection in early pregnancy: prenatal prediction and postnatal outcome

Prediction of postnatal outcomes of congenital cytomegalovirus infection is challenging during pregnancy. We evaluated the prognostic performance of prenatal assessment to predict symptoms at birth and long-term sequelae, including different machine learning techniques. Monocentric single-centre study including pregnant women referred for fetal infection following maternal infection (MPI) in early pregnancy. Fetal infection was diagnosed by CMV-PCR in amniotic fluid from 17 weeks'. Secondary prevention by valaciclovir was offered from Oct 2019. Prenatal follow-up of infected fetuses was by serial ultrasound every two weeks until delivery. Fetal MRI was performed at 26-28 weeks and again at 32-33 weeks of gestation. Tertiary prevention was systematically offered using valaciclovir or valganciclovir based on prenatal findings. All newborns were tested for infection and related symptoms at birth. 182 cases of fetal infection following MPI at mean 7 (5; 9) weeks' were enrolled between Jan 2009 and Dec 2022. 19 women received secondary prevention. 119 underwent tertiary prevention, including 108 using valaciclovir. 40 pregnancies were terminated due to symptomatic fetuses or maternal distress. There were 4 IUFD and one spontaneous abortion. Postmortem data were available for 37/45 stillbirths. 137 live newborns were delivered. At birth, 62 of them were symptomatic, and 56 also tested positive for CMV-PCR. 45 newborns were treated after birth. At least one year into life, 42 were symptomatic, including 5 with developmental delays and 3 with vestibular dysfunction. The prognosis of infected fetuses appears to be associated with prenatal imaging, with an increased risk of adverse outcomes linked to severe prenatal features. Prognosis is highly influenced by early prenatal treatment, especially in cases of mild prenatal findings. We report a large monocentric cohort study. Prediction of postnatal outcome using ultra-deep standardised phenotyping seems to be influenced by prenatal antiviral therapy.