First trimester universal one-time serology screening for cytomegalovirus. A pilot study at two tertiary referral centers in Barcelona (Catalunya, Spain).

Abstract

Introduction Congenital cytomegalovirus (cCMV) is the main infectious cause of sensorineural hearing loss and neurodevelopmental disability. First-trimester and periconceptional period are the most vulnerable times for fetal injury. Universal serological cytomegalovirus (CMV) screening in pregnant women is not currently recommended. After a recent randomized controlled clinical trial that demonstrated a 70% reduction of vertical transmission with high-dose valacyclovir (VCV), a pilot first-trimester screening program was launched at our setting. Methods This epidemiological surveillance study was conducted at two tertiary hospitals in Barcelona. The primary outcome was to evaluate the results of the first two years of implementation of a universal first-trimester CMV screening program. The secondary outcome was to assess maternal seroprevalence, and the burden of primary infection during the fetal risk period in this population. IgG and IgM antibodies were determined in first-trimester pregnant women at the time of the Combined Test for aneuploidy. In those with positive IgG and IgM, IgG avidity was performed through a fast alert system. Low or intermediate avidity was considered as primary infection in the first-trimester or periconceptional period, and women were offered VCV up to the time of amniocentesis. Infected fetuses were followed-up according to our clinical protocol. Results From February 2021 to August 2023, 2 777 first-trimester pregnant women between 8+0 and 13+6 gestational weeks were screened. Maternal IgG seroprevalence was 70.6%. Among these, 22 (0.8%) had IgM antibodies, four with low or intermediate avidity, suggesting a recent primary infection, and they received oral VCV 2g/6h. Vertical transmission occurred in one with a delayed start of VCV treatment and the family opted for termination of pregnancy. Conclusions Universal first-trimester CMV screening is feasible. A high seroprevalence was observed in our population. Larger studies will confirm whether screening is cost-effective in our setting.