Background:We analyzed both early and late (persistent) phases of each cytomegalovirus (CMV) antibody in mothers with primary CMV infection during pregnancy and subsequent congenital CMV infection for a long period from late pregnancy to after delivery using our stored serum samples. Methods: We used stored serum samples obtained during pregnancy to after delivery from mothers with CMV immunoglobulin (Ig) G seroconversion and subsequent infant congenital CMV infection. CMV antibodies, including CMV IgG titer, IgM titer, and IgG avidity, were assessed using the Denka IgG assay, Denka IgM assay Ver.1 and Ver.2, and Enzygnost IgG assay and Denka IgG avidity assay, respectively. We analyzed the dynamics of each CMV antibody for a long period from late pregnancy to after delivery and correlations of each antibody, calculating Pearson's correlation coefficients (R 2 ). Results: We used 67 serum samples obtained from 12 included participants between 2013 and 2018. CMV IgG increased until 61 weeks and did not change significantly after. CMV IgM decreased until 52 weeks and did not change significantly after that in both assays. CMV IgG avidity increased until 64 weeks and did not change significantly after that in both assays. In CMV IgM, a strong positive correlation was found (R 2 = 0.9326) between the two different IgM assays. Serum results of the late phase (after 60 weeks) were subsumed into the area of high CMV IgG avidity and low CMV IgM titer, which probably was equivalent to the persistent IgM. Conclusions: CMV antibodies in mothers during the late phase of primary infection were in high IgG avidity and low IgM titer, which probably was equivalent to the persistent IgM.

Background: There are no detailed reports in the literature on maternal cytomegalovirus antibody screening for universal newborn hearing screening (UNHS) referral patients. We examined maternal cytomegalovirus antibody screening results and estimated the incidence of maternal primary cytomegalovirus infection among UNHS referral patients. Methods: During September 2013-March 2021, fresh urine samples were collected in the first week after birth from 98 neonates with UNHS referral results at 15 obstetrical institutions in Mie, Japan (the first hearing screening). We performed a real-time polymerase chain reaction analysis to detect cytomegalovirus DNA in the samples. Infants with ≥200 copies/mL of cytomegalovirus DNA were diagnosed with congenital cytomegalovirus (cCMV) infection. A second hearing screening was performed, and patients with positive results were sent to the otorhinolaryngologists for further examinations of congenital hearing loss. We calculated incidence rates (%) with 95% confidence intervals (CIs) for cCMV infection among patients with UNHS referral results and maternal primary cytomegalovirus infection among patients who underwent maternal cytomegalovirus antibody screening. Results: Among the 98 neonates with UNHS referral results (the first hearing screening), 5 were diagnosed with cCMV infection (incidence rate: 5.1%; 95% CI: 0.8-9.5). All five patients with cCMV had positive second hearing screening results and were sent to their otorhinolaryngologists. All five were diagnosed with congenital hearing loss, and four were diagnosed with congenital hearing loss secondary to cCMV infection. The remaining patient with cCMV infection was diagnosed with congenital hearing loss unrelated to cCMV infection. Of the 98 patients, 60 underwent maternal cytomegalovirus antibody screening. Among the 60 patients, six had maternal primary cytomegalovirus infection during pregnancy (incidence rate: 10.0%; 95% CI: 2.4-17.6). Of the six patients, four were positive for cytomegalovirus immunoglobulin (CMV Ig) G and IgM antibodies in maternal blood with low CMV IgG antibody avidity results during early pregnancy, while the remaining two had maternal CMV IgG antibody seroconversion during pregnancy. Conclusions: This is the first study to examine the maternal primary cytomegalovirus infection incidence rate in patients with UNHS referral results (the first hearing screening). We identified a 10-fold higher risk in this population (10.0%) than in the general population (0.98%).

Cytomegalovirus (CMV) is associated with congenital infections. We aimed to validate the revised CMV immunoglobulin (Ig) M titer cutoff for IgG avidity measurements as a reflex test in maternal screening to identify women with primary CMV infection and newborn congenital cytomegalovirus (cCMV). We screened maternal CMV antibodies (the Denka assay) in Japan, from 2017 to 2019, using a revised IgM cutoff (≥4.00 index). Participants were tested for IgG and IgM antibodies, and for IgG avidity if IgM levels exceeded the cutoff. We compared these with corresponding results from 2013 to 2017 based on the original cutoff (≥1.21) and recalculated using the revised cutoff. Newborn urine CMV DNA tests were performed for women with low avidity (≤35.0%). Among 12,832 women screened in 2017–2019, 127 (1.0%) had IgM above the revised cutoff. Thirty-five exhibited low avidity, and seven infants developed cCMV. Of 19,435 women screened in 2013–2017, 184 (1.0%) had IgM above the revised cutoff, 67 had low avidity, and 1 had cCMV. The 2017–2019 results were not significantly different from the 2013–2017 results. The revised IgM cutoff improves maternal screening in identifying primary infection and newborn cCMV; however, further study related to other assays than Denka is required.

This study evaluated the impact of the coronavirus disease 2019 (COVID-19) pandemic on the occurrence of maternal primary cytomegalovirus (CMV) infection in Japan. We performed a nested case-control study using data from maternal CMV antibody screening under the Cytomegalovirus in Mother and infant-engaged Virus serology (CMieV) program in Mie, Japan. Pregnant women with negative IgG antibodies at ≤20 weeks of gestation who were retested at ≥28 weeks were enrolled. The study period was divided into 2015–2019 as the pre-pandemic and 2020–2022 as the pandemic period, and the study site included 26 institutions conducting the CMieV program. The incidence rate of maternal IgG seroconversion was compared between the pre-pandemic (7008 women enrolled) and pandemic (2020, 1283 women enrolled; 2021, 1100 women; and 2022, 398 women) periods. Sixty-one women in the pre-pandemic period and five, four, and five women during 2020, 2021, and 2022, respectively, showed IgG seroconversion. The incidence rates in 2020 and 2021 were lower (p < 0.05) than that in the pre-pandemic period. Our data suggest a transient decrease in the incidence of maternal primary CMV infection in Japan during the COVID-19 pandemic, which could be due to prevention and hygiene measures taken at the population level.