Giuseppe Maria Maruotti

Background: Maternal diabetes is associated with several adverse perinatal outcomes, but its relationship with hypoxic-ischaemic perinatal injury remains poorly defined. Fetal compromise may reflect an acute intrapartum event, a chronic antepartum process, or both. Objective: To systematically review the evidence linking gestational diabetes mellitus (GDM) and pregestational diabetes to hypoxic-ischaemic perinatal injury, assessing diagnosed or coded neonatal brain injury, acid–base status at birth, and chronic antepartum markers separately. Methods: PubMed, Embase, and Scopus were searched from inception to 16 October 2026. Observational studies comparing pregnancies with and without diabetes and reporting diagnosed or coded hypoxic-ischaemic encephalopathy, neonatal encephalopathy or neonatal seizures, umbilical acid–base status, or a chronic marker of fetal hypoxia were eligible; studies reporting only Apgar-based or other non-specific outcomes were excluded. Risk of bias was assessed with the Newcastle–Ottawa Scale together with a separate judgement of outcome-definition adequacy, certainty of evidence was rated with GRADE, and synthesis followed the SWiM guideline, with vote counting by direction of effect. The protocol was registered in PROSPERO (CRD420261435362). Results: Seventy-four studies were included (30 GDM only, 12 pregestational diabetes only, 32 both or unspecified). Pregestational diabetes was associated with hypoxic-ischaemic encephalopathy, neonatal encephalopathy, or neonatal seizures in all five studies with sufficient events (adjusted odds or risk ratios 1.5–5.1; very low certainty). In GDM, estimates pointed in an adverse direction in six of seven informative comparisons but were mostly small and imprecise; statistically significant associations came only from a large registry (adjusted relative risk 1.24–1.25) and a study restricted to small-for-gestational-age infants (very low certainty). Umbilical acid–base status was less favourable in pregestational diabetes in 9 of 10 studies. In GDM, differences were small (less favourable in 13 of 17 comparisons; pooled mean difference in umbilical arterial pH −0.025, 95% CI −0.041 to −0.010, prediction interval −0.10 to 0.05, three studies; very low certainty for clinically relevant acidaemia). Chronic markers pointed in an adverse direction in 33 of 37 independent evidence sources, most consistently erythropoietin, nucleated red cells, and polycythaemia, but certainty was very low for every marker. No study documented a chronic marker, an identified acute event, and diagnosed or coded brain injury in the same fetus. Conclusions: Pregestational diabetes is associated with diagnosed or coded hypoxic-ischaemic encephalopathy, neonatal encephalopathy, or seizures and with markers of chronic fetal hypoxic stress, but the certainty of this evidence is very low. In GDM, estimates for these outcomes mostly point in an adverse direction but are small and imprecise (very low certainty), and acid–base differences at birth are small. Whether a chronic process and an acute event combine to cause injury in an individual fetus has not been studied.

Background and Objectives: Congenital cytomegalovirus (CMV) infection following primary maternal infection in the first trimester carries the highest risk of long-term sequelae, yet prenatal diagnosis depends on amniotic fluid polymerase chain reaction (PCR), which cannot be performed before 17 weeks. Detection of CMV in chorionic villi at 11–14 weeks has been proposed to bring this information forward and to exclude CMV-related embryopathy. We systematically reviewed the published studies that have evaluated this test in order to determine its diagnostic accuracy. Materials and Methods: We conducted a systematic review of diagnostic test accuracy (PROSPERO CRD420261482510), and reported according to PRISMA-DTA. Five databases were searched up to 19 August 2026 without language or date restrictions. Eligible studies enrolled pregnancies with documented primary maternal infection and allowed reconstruction of a two-by-two table against CMV DNA in neonatal urine and/or saliva within three weeks of birth (with fetal or placental tissue accepted for pregnancies ending in termination). Screening, extraction and QUADAS-2 assessment were performed in duplicate and blinded. Overlapping cohorts were reduced to the largest, most completely verified report. Wilson score confidence intervals (CIs) were used; pooling was pre-specified only for four or more independent datasets. Results: Of 704 unique records, three independent cohorts in three primary publications were eligible, contributing 340 villus samples. The largest cohort (n = 330) gave a sensitivity of 40.5% (95% CI 27.0–55.5), specificity of 99.3% (97.5–99.8), positive predictive value of 89.5%, and negative predictive value of 92.0% at a prevalence of 12.7%. The remaining cohorts contributed four and six samples in turn, all true negatives. No study was at low risk of bias in all four QUADAS-2 domains; the cohort carrying the sensitivity estimate was at high risk in two, including verification of terminated pregnancies on placental tissue, whose net effect on sensitivity cannot be determined from the published data. Certainty was very low throughout. Conclusions: CMV PCR on chorionic villi is highly specific but misses approximately three infected fetuses in five, so a negative result does not reliably exclude congenital infection, and the proposition that it excludes embryopathy is unevaluated. Based on current evidence, it should not be used as a standalone basis for first-trimester decisions about continuing a pregnancy.

Background: Neonatal encephalopathy (NE) is a major cause of neonatal mortality and long-term neurological disability. Although hypoxic–ischaemic encephalopathy (HIE) is the most common cause, several genetic disorders may mimic or coexist with hypoxic–ischaemic injury. Next-generation sequencing has emerged as a promising diagnostic tool in this setting. This systematic review evaluated the current evidence on genomic sequencing in NE. Material and methods: A systematic review was conducted according to PRISMA 2020 guidelines and prospectively registered in PROSPERO. PubMed/MEDLINE, Embase, and Scopus were searched from inception to June 2026. Eligible studies included neonates (≤28 days) with NE, suspected or confirmed HIE, HIE mimics, or unexplained NE who underwent genomic sequencing. Whole-exome sequencing (WES), whole-genome sequencing (WGS), clinical exome sequencing (CES), rapid genomic sequencing, and targeted next-generation sequencing panels were considered. Study quality was assessed using the Newcastle–Ottawa Scale. Results: Seven studies met the inclusion criteria. Considerable heterogeneity was observed regarding patient selection, sequencing strategies, and reported outcomes. Among diagnostic sequencing studies, diagnostic yield ranged from 23.5% to 53.1%. Pathogenic and likely pathogenic variants were identified in genes associated with developmental and epileptic encephalopathies, metabolic disorders, mitochondrial diseases, and neurodevelopmental syndromes, including SCN2A, KCNQ2, CACNA1A, STXBP1, PTPN11, BCOR, MMUT, COQ2, and GBE1. Genomic sequencing frequently refined or changed the initial diagnosis, improved prognostic assessment and genetic counselling, and, in selected cases, guided disease-specific treatment. One study investigated genetic susceptibility to hypoxic–ischaemic injury rather than diagnostic sequencing. Conclusions: Genomic sequencing provides clinically meaningful diagnoses in a substantial proportion of neonates with unexplained NE or atypical HIE presentations. Current evidence supports integrating genomic sequencing into the diagnostic evaluation of selected infants, although larger prospective studies are needed to define its optimal timing, clinical utility, and cost-effectiveness.

Background: Monochorionic twin pregnancies provide a unique model to investigate fetal phenotypic discordance, because both fetuses share a single placenta and interconnected vascular circulation. Although most monochorionic twins are monozygotic, clinically relevant differences may arise through genetic, epigenetic, placental, and stochastic developmental mechanisms. Methods: This systematic review was conducted according to PRISMA 2020 and registered in PROSPERO (CRD420261432361). PubMed/MEDLINE, Embase, and Scopus were searched from inception to June 2026. Eligible studies included monochorionic monozygotic twin pairs with discordant congenital, developmental, or syndromic phenotypes, confirmed or clearly inferable monochorionicity, and at least one genomic, cytogenetic, or epigenetic investigation; studies describing confirmed monochorionic dizygotic twinning were excluded. Findings were synthesized qualitatively. Results: The search identified 1357 records. After duplicate removal and screening, 48 studies fulfilled the eligibility criteria, comprising 441 monozygotic twin pairs; 37 were single-pair case reports, whereas one large retrospective cohort study alone contributed 193 pairs (44% of the entire pooled sample). Reported phenotypes included congenital heart disease, chromosomal abnormalities, disorders of sex development, imprinting disorders, neurodevelopmental disease, endocrine disorders, renal anomalies, skeletal disorders, and multisystem malformations. Molecular methods included karyotyping, FISH, chromosomal microarray, array-CGH, CNV analysis, WES, WGS, targeted sequencing, and methylation profiling. Proposed mechanisms included postzygotic chromosomal errors, somatic mutations, tissue-specific mosaicism, discordant or shared CNVs, differential methylation, imprinting defects, variable expressivity, blood chimerism, unequal placental sharing, TTTS, TAPS, sFGR, and uteroplacental insufficiency. Conclusions: Phenotypic discordance in monochorionic twins is rarely explained by a single mechanism. Available evidence supports a multifactorial model in which postzygotic genetic events, epigenetic regulation, placental vascular factors, and stochastic developmental processes interact.

Objective: To assess correlations between maternal obesity and fetal interventricular septum (IVS) volume measured by means of spatiotemporal image correlation and Virtual Organ Computer-Aided Analysis (STIC-VOCAL), after adjustment for gestational age. Methods: This cross-sectional observational study included 88 consecutive singleton pregnancies undergoing routine obstetric ultrasound at our center between January 2024 and December 2025. Fetal IVS volume was assessed using STIC-VOCAL, and its association with maternal characteristics was evaluated by means of univariate and multivariable regression analyses adjusted for gestational age. Results: Fetal IVS volume increased with estimated fetal weight (r = 0.860, p < 0.0001) and gestational age (r = 0.891, p < 0.0001), which represented the main determinant of absolute fetal cardiac volume. The association between maternal obesity and fetal IVS volume was not evident on univariate analysis (U = 987.5, p = 0.874) but became significant after adjustment for gestational age in multivariable regression models (β = +89.1 mm³, p < 0.0001). At comparable gestational ages, maternal obesity was associated with an adjusted increase in fetal IVS volume of approximately 22.6 mm³. Conclusions: Maternal obesity was independently associated with a modest increase in fetal IVS volume after adjustment for gestational age. STIC-VOCAL volumetry may provide a sensitive tool for detecting subtle fetal cardiac structural changes, although these findings remain exploratory.

Objectives: Autism spectrum disorder (ASD) is increasingly conceptualized as a neurodevelopmental condition with prenatal origins. Advances in fetal magnetic resonance imaging (MRI), including high-resolution structural imaging and resting-state functional connectivity analysis, now enable in vivo characterization of the developing human brain before birth. This review examines whether fetal MRI biomarkers are associated with later ASD diagnosis or autistic traits. Methods: We conducted a PRISMA-informed narrative review of human studies identified through MEDLINE, EMBASE, SCOPUS, and Web of Science. Eligible studies included original human investigations using fetal MRI to assess brain structure and/or function, with postnatal ASD diagnosis or standardized autistic-trait outcomes. Results: Eight eligible studies provide converging evidence that neurodevelopmental divergence associated with ASD may be detectable in utero. Structural analyses consistently report prenatal volumetric alterations, particularly enlargement of the insular cortex between the second and third trimesters. Additional findings of regional overgrowth and hemispheric asymmetries suggest distributed deviations in cortical maturation. Functional fetal MRI studies further demonstrate atypical large-scale network organization prior to birth. Altered connectivity within cingulate, prefrontal, temporal, and cerebellar circuits has been prospectively associated with later autistic traits, indicating that network-level integration may diverge before behavioral symptoms emerge. Evidence from high-risk conditions, including isolated ventriculomegaly and tuberous sclerosis complex, reinforces the association between prenatal structural abnormalities and increased ASD risk. Conclusions: Current evidence suggests that structural and functional brain alterations identifiable by fetal MRI may precede the clinical manifestation of ASD. These findings support a model of ASD as a condition potentially rooted in prenatal neurodevelopmental divergence. However, larger, standardized, multicenter studies are required before fetal MRI biomarkers can be translated into predictive or clinical applications.

Background: Echocardiography currently represents the gold standard for the anatomical and functional assessment of the fetal heart by experienced operators. FetalHQ (VolusonTM) provides a semi-automated speckle-tracking analysis of the fetal heart with promising results for the reliable assessment of cardiac remodeling, specifically of size, shape, and contractility. Methods: We conducted a retrospective study comparing 108 controls, 119 obesity (BMI ≥ 30), 69 pre-pregnancy diabetes mellitus (DM), 41 gestational diabetes mellitus (GDM), and 37 early fetal growth restriction (FGR) cases (19+0–22+6 weeks). FetalHQ was utilized during midtrimester echocardiographic exams to evaluate fetal myocardial thickness and left ventricular mass. Results: Myocardial thickness was increased in DM (median 0.21 [IQR 0.17–0.23] cm) vs. controls (0.17 [0.15–0.21] cm; p < 0.01) and reduced in FGR (0.13 [0.11–0.18] cm; p < 0.01). Left ventricular mass increased in obesity (0.98 [0.62–1.19] g) and DM (1.12 [0.94–1.17] g) vs. controls (0.73 [0.56–0.97] g; both p < 0.01). Conclusions: Fetal cardiac remodeling, especially myocardial thickness and left ventricular mass adaptations, is detectable in fetuses from high-risk pregnancies starting from the second trimester. Advanced speckle-tracking techniques, such as fetalHQ, provide valuable early risk stratification and may support the need for systematic fetal cardiac screening and monitoring during gestation in selected groups of patients.

Pregnancies complicated by diabetes, including pregestational and gestational diabetes mellitus, are associated with increased maternal and fetal morbidity. Early identification of at-risk pregnancies is crucial for timely intervention and improved outcomes. Emerging evidence highlights the interplay of genetic predisposition, epigenetic modifications, and non-invasive biomarkers in the early detection of diabetic pregnancies. Genetic factors influencing insulin signaling, glucose metabolism, and pancreatic β-cell function may contribute to susceptibility to gestational hyperglycemia. Concurrently, epigenetic alterations, such as DNA methylation and histone modifications in maternal and placental tissues, have been linked to dysregulated metabolic pathways and adverse pregnancy outcomes. Non-invasive biomarkers, including circulating cell-free DNA and microRNAs in maternal blood, show promise for early diagnosis by offering a safer and more practical alternative to invasive testing. Integrating genetic, epigenetic, and molecular marker data could enhance risk stratification and enable personalized monitoring and management strategies. This review synthesizes current knowledge on the molecular underpinnings of diabetic pregnancies, evaluates the potential of emerging biomarkers for early diagnosis, and discusses the challenges and future perspectives for translating these findings into clinical practice. Understanding these mechanisms may pave the way for precision medicine approaches, ultimately improving maternal and neonatal outcomes in pregnancies affected by diabetes.

Human cytomegalovirus (HCMV) is a herpesvirus (family) belonging to the beta herpesvirus subfamily that causes significant morbidity both in immunocompromised hosts (horizontal transmission) and during vertical transmission from mother to child. HCMV has the ability to establish a permanent latent infection with its host (even for decades), in which the DNA remains as a silent nuclear episome (latent phase) until reactivation after the appropriate conditions have occurred (lytic phase). The transition between the two phases (latent/lytic) is largely determined by the type of infected cell and the health status of the host, which ultimately corresponds to the epigenetic state of the infected cells. Lytic infection of the virus normally occurs in epithelial cells, endothelial cells, fibroblasts or macrophages, whereas the latent phase occurs when undifferentiated cells of the myeloid lineage, such as CD34+ hematopoietic progenitor cells, are infected. Epigenetic regulation of the viral genome begins with the formation of chromatin in the viral DNA just 30 min after infection and then evolves towards the latent or lytic phase. DNA viruses, including members of the herpesvirus family, are currently the subject of intense study regarding the role that epigenetics plays in controlling the viral life cycle, focusing primarily on the role of post-translational modifications (PTMs) of histones, as well as DNA methylation. Within the viral genome, nucleosomes are organized for the spatial/temporal expression of appropriate genes due to epigenetic modifications. Therefore, during the infection cycle, DNA chromatinization and chromatin modifications influence the expression of genes in the HCMV genome. This process is mediated by (i) enzymes called “writers”, which catalyze PTMs by adding chemical groups to proteins (acetylation, methylation, etc.); (ii) recruitment of specific transcription factors called “readers”, that bind to modified amino acid residues of proteins and act as interpreters of the PTM code; and (iii) “erasers”, enzymes that remove these modifications (e.g., HDACs). Indeed, recent advances in understanding the chromatin-based mechanisms of viral infections offer some promising strategies for therapeutic intervention that could be particularly useful in immunosuppressed recipients of transplants to avoid allograft rejection and infection by other opportunistic pathogens. In this review, we comprehensively examine the epigenetic regulation of the HCMV genome across distinct phases of viral infection, with particular attention to recent studies that significantly enriched the current knowledge about molecular mechanisms and future therapeutic perspectives.