Human Cytomegalovirus in breast milk is associated with milk composition, the infant gut microbiome, and infant growth.

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus that is often transmitted to the neonate via breast milk. Postnatal CMV transmission can have negative health consequences for preterm and immunocompromised infants, but any effects on healthy term infants are thought to be benign. Furthermore, the impact of CMV on the composition of the hundreds of bioactive factors in human milk has not been tested. Here, we utilize a cohort of exclusively breastfeeding full term mother-infant pairs to test for differences in the milk transcriptome and metabolome associated with CMV, and the impact of CMV in breast milk on the infant gut microbiome and infant growth. We find upregulation of the indoleamine 2,3- dioxygenase (IDO) tryptophan-to-kynurenine metabolic pathway in CMV+ milk samples, and that CMV+ milk is associated with decreased Bifidobacterium in the infant gut. Our data indicate a complex relationship between milk CMV, milk kynurenine, and infant growth; with kynurenine positively correlated, and CMV viral load negatively correlated, with infant weight-for-length at 1 month of age. These results suggest CMV transmission, CMV-related changes in milk composition, or both may be modulators of full term infant development.

Human milk variation is shaped by maternal genetics and impacts the infant gut microbiome.

Human milk is a complex mix of nutritional and bioactive components that provide complete nutrition for the infant. However, we lack a systematic knowledge of the factors shaping milk composition and how milk variation influences infant health. Here, we used multi-omic profiling to characterize interactions between maternal genetics, milk gene expression, milk composition, and the infant fecal microbiome in 242 exclusively breastfeeding mother-infant pairs. We identified 487 genetic loci associated with milk gene expression unique to the lactating mammary gland, including loci that impacted breast cancer risk and human milk oligosaccharide concentration. Integrative analyses uncovered connections between milk gene expression and infant gut microbiome, including an association between the expression of inflammation-related genes with IL-6 concentration in milk and the abundance of Bifidobacteria in the infant gut. Our results show how an improved understanding of the genetics and genomics of human milk connects lactation biology with maternal and infant health.

Bacterial, fungal, and interkingdom microbiome features of exclusively breastfeeding dyads are associated with infant age, antibiotic exposure, and birth mode.

The composition and function of early life gut bacterial communities (microbiomes) have been proposed to modulate health for the long term. In addition to bacteria, fungi (mycobiomes) also colonize the early life gut and have been implicated in health disorders such as asthma and obesity. Despite the potential importance of mycobiomes in health, there has been a lack of study regarding fungi and their interkingdom interactions with bacteria during infancy. The goal of this study was to obtain a more complete understanding of microbial communities thought to be relevant for the early life programming of health. Breastmilk and infant feces were obtained from a unique cohort of healthy, exclusively breastfeeding dyads recruited as part of the Mothers and Infants Linked for Healthy Growth (MILk) study with microbial taxa characterized using amplicon-based sequencing approaches. Bacterial and fungal communities in breastmilk were both distinct from those of infant feces, consistent with niche-specific microbial community development. Nevertheless, overlap was observed among sample types (breastmilk, 1-month feces, 6-month feces) with respect to the taxa that were the most prevalent and abundant. Self-reported antibacterial antibiotic exposure was associated with micro- as well as mycobiome variation, which depended upon the subject receiving antibiotics (mother or infant), timing of exposure (prenatal, peri- or postpartum), and sample type. In addition, birth mode was associated with bacterial and fungal community variation in infant feces, but not breastmilk. Correlations between bacterial and fungal taxa abundances were identified in all sample types. For infant feces, congruency between bacterial and fungal communities was higher for older infants, consistent with the idea of co-maturation of bacterial and fungal gut communities. Interkingdom connectedness also tended to be higher in older infants. Additionally, higher interkingdom connectedness was associated with Cesarean section birth and with antibiotic exposure for microbial communities of both breastmilk and infant feces. Overall, these results implicate infant age, birth mode, and antibiotic exposure in bacterial, fungal and interkingdom relationship variation in early-life-relevant microbiomes, expanding the current literature beyond bacteria.

Chromosomal microarray analysis in the investigation of prenatally diagnosed congenital heart disease.

BACKGROUND: Chromosomal microarray analysis has emerged as a primary diagnostic tool in prenatally diagnosed congenital heart disease and other structural anomalies in clinical practice. OBJECTIVE: Our study aimed to investigate the diagnostic yield of microarray analysis as a first-tier test for chromosomal abnormalities in fetuses with both isolated and nonisolated congenital heart disease and to identify the association of different pathogenic chromosomal abnormalities with different subgroups of congenital heart disease. STUDY DESIGN: Retrospective data from 217 pregnancies that were diagnosed with congenital heart disease between 2011 and 2016 were reviewed. All pregnancies were investigated with the use of microarray analysis during the study period. Classification of chromosomal abnormalities was done based on American College of Medical Genetics and Genomics guidelines into (1) pathogenic chromosomal abnormalities that included numeric chromosomal abnormalities (aneuploidy and partial aneuploidy) and pathogenic copy number variants (22q11.2 deletion and other microdeletions/microduplications), (2) variants of uncertain significance, and (3) normal findings. RESULTS: Our study found a detection rate for pathogenic chromosomal abnormalities (numeric and pathogenic copy number variants) of 36.9% in pregnancies (n=80) that were diagnosed prenatally with congenital heart disease who underwent invasive testing with chromosomal microarray. The detection rate for numeric abnormalities was 29.5% (n=64) and for pathogenic copy number variants was 7.4% (n=16) of which 4.2% were 22q11.2 deletion and 3.2% were other pathogenic copy number variants, most of which theoretically could have been missed by the use of conventional karyotype alone. Pathogenic copy number variants were most common in conotruncal defects (19.6%; 11/56) that included 42.9% in cases of interrupted aortic arch, 23.8% in cases of tetralogy of Fallot, 13.3% in cases of transposition of the great arteries, and 8.3% in cases of double outlet right ventricle. Of these changes, 81.8% were 22q11.2 deletion, and 18.2% were other microdeletions/microduplications. After conotruncal defects, pathogenic copy number variants were most common in right ventricular outflow tract and left ventricular outflow tract groups (8% and 2.2%, respectively) in which none were 22q11.2 deletion. Pathogenic chromosomal abnormalities (numeric and pathogenic copy number variants) detected by chromosomal microarray analysis were significantly more common in the nonisolated congenital heart disease group (64.5%; n=49) compared with the isolated group (22%; n=31; P<.001). CONCLUSION: In pregnancies that were diagnosed with congenital heart disease and had undergone diagnostic genetic testing, our study showed that chromosomal microarray analysis has an added value in the detection of pathogenic chromosomal abnormalities compared with conventional karyotype, particularly in cases of pathogenic copy number variants. This yield is influenced not only by the type of congenital heart disease but also by the presence of extracardiac anomalies.

Preterm Birth of Infants Prenatally Diagnosed with Congenital Heart Disease, Characteristics, Associations, and Outcomes.

There are limited data on the relation between congenital heart disease (CHD) and preterm birth (PTB). We aimed to estimate the risk of PTB in newborns with CHD, to study associations and risk factors (modifiable and non-modifiable) as well as investigate postnatal outcomes. This was a retrospective cohort study of 336 pregnancies diagnosed with CHD between 2011 and 2016. Groups consisted of those delivered at or after 37 weeks, and those who delivered prior to 37 weeks. Collected data included maternal and fetal characteristics as well postnatal outcomes. Complete data were obtained from 237 singleton pregnancies. The overall proportion of PTB was 23.2% for all CHD, of which 38.2% were spontaneous PTB which was almost unchanged after excluding extracardiac anomalies and pathogenic chromosomal abnormalities. Significant non-modifiable risk factors were pregnancy-related HTN disorders (P < 0.001), fetal growth restriction (P = 0.01), and pathogenic chromosomal abnormalities (P = 0.046). Significant PTB modifiable risk factors included prenatal marijuana use (P = 0.01). Pregnancies delivered at 37-38 weeks had significantly more newborns with birthweight < 2500 g (P < 0.001), required more pre-operative NICU support including intubation (P = 0.049), vasopressors (P = 0.04), prostaglandins (P = 0.003), antibiotics (P = 0.01), and had longer hospital stay (P = 0.001) than those delivered at ≥ 39 weeks. Prenatally diagnosed pregnancies with CHD had higher PTB rate compared to the general population, with spontaneous PTB comprising 38.2% of these preterm deliveries. Most PTB risk factors were non-modifiable, however, significant modifiable factors included marijuana use in pregnancy. Outcomes were favorable in neonates delivered at or beyond 39 weeks.