Midtrimester microbial DNA variations in maternal serum of women who experience spontaneous preterm birth

Association between maternal family history of hypertension and preterm birth: modification by noise exposure and multivitamin intake

OBJECTIVE

To measure the effect of maternal family history of hypertension on preterm birth (PTB) and to identify factors that modified this association.

METHODS

A case-control study was nested in a prospective cohort of the entire pregnant population in Wuhan, China, from 2011 to 2013. Home-visit interviews were scheduled for all PTBs and their controls, to collect extensive information on maternal exposures to behavioral, environmental, and intergenerational risk factors of PTB. The effects of maternal family history of hypertension on PTB were measured by logistic regression analyses, controlling for potential confounders. Potential effect modifiers were examined using stratified analyses.

RESULTS

There were 2393 PTBs and 4263 full-term births out of all eligible births. A positive association was observed between maternal family history of hypertension and PTB, after adjusted for potential confounders (adjusted odds ratio: 1.17 [1.03, 1.33]). A higher effect was observed when mothers were exposed to certain noise during pregnancy (adjusted odds ratio: 1.37 [1.14, 1.65]) and/or when they did not take multivitamins during pregnancy (adjusted odds ratio: 1.46 [1.20, 1.78]), whereas, this association was weaker and no longer significant when mothers took multivitamins during pregnancy (adjusted odds ratio: 1.00 [0.84, 1.19]) and/or when they were not exposed to certain noise during pregnancy (adjusted odds ratio: 1.01 [0.85, 1.12]). The modification effect from maternal multivitamin intake was significant on both spontaneous and medically indicated PTBs, and the modification effect from maternal exposure to certain noise was only significant on spontaneous PTB.

CONCLUSIONS

Increased PTB risk was observed for pregnant women with a family history of hypertension in Wuhan, China. This effect was stronger when pregnant women did not take multivitamin and/or exposed to certain noise during pregnancy, than those who took multivitamin and/or unexposed to certain noise.

Human Blood Bacteriome: Eubiotic and Dysbiotic States in Health and Diseases

The human gut microbiome is acknowledged as being associated with homeostasis and the pathogenesis of several diseases. Conventional culture techniques are limited in that they cannot culture the commensals; however, next-generation sequencing has facilitated the discovery of the diverse and delicate microbial relationship in body sites and blood. Increasing evidence regarding the blood microbiome has revolutionized the concept of sterility and germ theory in circulation. Among the types of microbial communities in the blood, bacteriomes associated with many health conditions have been thoroughly investigated. Blood bacterial profiles in healthy subjects are identified as the eubiotic blood bacteriome, whereas the dysbiotic blood bacteriome represents the change in bacterial characteristics in subjects with diseases showing deviations from the eubiotic profiles. The blood bacterial characteristics in each study are heterogeneous; thus, the association between eubiotic and dysbiotic blood bacteriomes and health and disease is still debatable. Thereby, this review aims to summarize and discuss the evidence concerning eubiotic and dysbiotic blood bacteriomes characterized by next-generation sequencing in human studies. Knowledge pertaining to the blood bacteriome will transform the concepts around health and disease in humans, facilitating clinical implementation in the near future.

Serum apolipoprotein A-II and alpha-2-antiplasmin levels in midtrimester can be used as predictors of preterm delivery

OBJECTIVE

To identify serum protein markers in midtrimester that predict preterm delivery.

METHODS

A retrospective case-control study randomly selected patients that experienced spontaneous preterm birth and healthy control patients that experienced a normal delivery at term. A proteomic analysis was undertaken using the data-independent acquisition method.

RESULTS

A total of 30 singleton pregnant women were randomly selected from 12 800 pregnant women: 15 women had a spontaneous preterm birth (group Y) and 15 age- and body mass index-matched women gave birth at term (group D). All of the patients provided serum at 15-20 weeks of gestation. A total of 39 differentially expressed proteins were identified. Compared with group D, 24 proteins were upregulated and 15 were downregulated in the preterm group Y. Using Kyoto Encyclopedia of Genes and Genomes pathway enrichment, the 24 upregulated proteins were significantly enriched in the complement and coagulation cascade pathways. Search Tool for the Retrieval of Interacting Genes Furthermore (STRING) analysis showed that apolipoprotein A-II (apoA-II) and alpha-2-antiplasmin (α2-AP), two upregulated proteins, were key nodes in the STRING protein-protein network.

CONCLUSIONS

These findings suggest that apoA-II and α2-AP might be new markers for predicting preterm delivery in the midtrimester.

Blood Microbial Communities During Pregnancy Are Associated With Preterm Birth

Microbial infection of the placenta, amniotic fluid, vaginal canal, and oral cavity is known to significantly contribute to preterm birth (PTB). Although microbes can be translocated into the blood, little is known regarding the blood microbiota during pregnancy. To assess changes in the microbiome during pregnancy, blood samples were obtained 2 or 3 times during pregnancy from a cohort of 45 pregnant women enrolled between 2008 and 2010. To analyze the association with PTB, we conducted a case-control study involving 41 pregnant women upon admission for preterm labor and rupture of membrane (20 with term delivery; 21 with PTB). Bacterial diversity was assessed in number and composition between the first, second, and third trimesters in term delivered women according to 16S rRNA gene amplicon sequencing, and data were analyzed using Quantitative Insight Into Microbial Ecology (QIIME). Taxonomy was assigned using the GreenGenes 8.15.13 database. Dominant microorganisms at the phylum level in all pregnant women were identified as Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. However, the number and composition of bacteria in women with PTB differed from that in women with term delivery. Firmicutes and Bacteroidetes were more abundant in women with PTB than in women with term delivery, while Proteobacteria was less prevalent in women with PTB. At the genus level, Bacteroides, Lactobacillus, Sphingomonas, Fastidiosipila, Weissella, and Butyricicoccus were enriched in PTB samples. These observational results suggest that several taxa in the maternal blood microbiome are associated with PTB. Further studies are needed to confirm the composition of the blood microbiota in women with PTB. Additionally, the mechanism by which pathogenic microbes in maternal blood cause infection and PTB requires further analysis.