Timing of primary maternal cytomegalovirus infection and rates of vertical transmission and fetal consequences.

OBJECTIVE: Cytomegalovirus infection is the most frequent congenital infection and a major cause of long-term neurologic morbidity. The aim of this meta-analysis was to calculate the pooled rates of vertical transmission and fetal impairments according to the timing of primary maternal infection. DATA SOURCES: From inception to January 2020, MEDLINE, Scopus, Cochrane Library, and gray literature sources were used to search for related studies. STUDY ELIGIBILITY CRITERIA: Cohort and observational studies reporting the timing of maternal cytomegalovirus infections and rate of vertical transmission or fetal impairments were included. The primary outcomes were vertical transmission and fetal insult, defined as either prenatal findings from the central nervous system leading to termination of pregnancy or the presence of neurologic symptoms at birth. The secondary outcomes included sensorineural hearing loss or neurodevelopmental delay at follow-up and prenatal central nervous system ultrasonography findings. STUDY APPRAISAL AND SYNTHESIS METHODS: The pooled rates of the outcomes of interest with their 95% confidence intervals (CI) were calculated for primary maternal infection at the preconception period, periconception period, first trimester, second trimester, and third trimester. RESULTS: A total of 17 studies were included. The pooled rates of vertical transmission (10 studies, 2942 fetuses) at the preconception period, periconception period, first trimester, second trimester, and third trimester were 5.5% (95% CI, 0.1-10.8), 21.0% (95% CI, 8.4-33.6), 36.8% (95% CI, 31.9-41.6), 40.3% (95% CI, 35.5-45.1), and 66.2% (95% CI, 58.2-74.1), respectively. The pooled rates of fetal insult in case of transmission (10 studies, 796 fetuses) were 28.8% (95% CI, 2.4-55.1), 19.3% (95% CI, 12.2-26.4), 0.9% (95% CI, 0-2.4%), and 0.4% (95% CI, 0-1.5), for maternal infection at the periconception period, first trimester, second trimester, and third trimester, respectively. The pooled rates of sensorineural hearing loss for maternal infection at the first, second, and third trimester were 22.8% (95% CI, 15.4-30.2), 0.1% (95% CI, 0-0.8), and 0% (95% CI, 0-0.1), respectively. CONCLUSION: Vertical transmission after maternal primary cytomegalovirus infection increases with advancing pregnancy, starting from the preconception period. However, severe fetal impairments are rare after infection in the first trimester of pregnancy.

Neonatal HCMV-related polymicrogyria in seroimmune women: What is the optimal pregnancy management?

BACKGROUND: Human cytomegalovirus (HCMV) infection is the most common congenital infection in developed countries. Recent studies highlighted similar percentages of symptoms in HCMV congenitally-infected infants following either primary or non-primary maternal infections. OBJECTIVES: To highlight correlation between neonatal brain abnormalities, detected by ultrasounds and magnetic resonance image in HCMV congenitally-infected infants, and maternal virological parameters during pregnancy, especially in seroimmune mothers. STUDY DESIGN: We considered the 36 HCMV congenitally-infected infants (26 asymptomatic and 10 symptomatic) referred to our center over 4 consecutive years. Maternal serologic data during pregnancy were available for all cases. Neonatal cranial ultrasound and magnetic resonance images were related to maternal virological findings during pregnancy. RESULTS: Polymicrogyria was observed in 6/10 (60.0%) symptomatic and 0/26 (0%) asymptomatic newborns (p < 0.001). The 6 infants with polymicrogyria were all born to mothers who were HCMV IgG reactive with negative specific IgM, in the first trimester of pregnancy (range: 8-14 weeks). For these six women, pre-conceptional HCMV serologic information were absent and they all were considered immune for HCMV during pregnancy, therefore no further serologic investigation or specific educational and hygienic information were recommended during gestation. CONCLUSION: These data highlight the elevated frequency of polymicrogyria in HCMV congenitally-infected infants born to mothers defined as seroimmune in the early stage of pregnancy and having no pre-existing serologic information. The paper stresses the potential utility of pre-conceptional screening to define maternal infection reliably (primary vs non-primary), and allow evidence-based counseling in women with positive serology, suggesting also preventive hygienic measures during pregnancy.

Visual sensory and ocular motor function in children with polymicrogyria: relationship to magnetic resonance imaging.

PURPOSE: To assess visual and ocular motor function in children with polymicrogyria (PMG). METHODS: The medical records of 15 children (0.4-4 years of age) with PMG documented by magnetic resonance imaging (MRI) and with age-corrected visual acuity measured by Teller acuity cards were reviewed retrospectively. Cortical function was assessed by pattern visually evoked potentials (VEP). Ocular motor function was assessed by video-oculography or clinical assessment. Results were compared to age-matched controls. RESULTS: Extent of PMG involvement varied from bilateral fronto-parietal to bilateral-diffuse. Nine children had involvement of the occipital lobe. Visual acuity at presentation was normal in 5 children (≥20/40 Snellen equivalent for age) and subnormal in 10 (average 20/200 equivalent). Visual acuity was similar in children with or without involvement of the occipital lobe (P = 0.4). Follow-up visual acuity was available for 9 children; 3 improved and 6 failed to improve (5 of whom had seizures). PMG involving the occipital lobe significantly reduced VEP amplitude and signal-to-noise ratios. Three infants without visually-guided behaviors had VEP responses. All 3 children with cytomegalovirus-related PMG without retinal disease had preserved visual function despite generalized MRI abnormalities. CONCLUSIONS: All children with PMG had recordable visual function either by visual acuity or VEP testing, however the majority did not show longitudinal improvement in acuity. Seizures may impose limits on visual acuity development. Children with cytomegalovirus-related PMG, microcephaly, and developmental delay can have normal visual acuity. Children with a recordable VEP but without visually guided behaviors may have a defect in sensorimotor transformation.