Findings from the integrative Human Microbiome Project offer new opportunities for risk assessment of women at risk of preterm birth.
Given that PTB worldwide occur in more then 10% of pregnancies (in Australia, that number is 8.5%) and has ongoing complications for the child into adolescence and adulthood, finding an early assessment to predict those high at risk of PTB is a critical maternal and public health measure.
Recent results published from researchers on the integrative Human Microbiome Project (iHMP) have generated data in one of the largest and most comprehensive multi-omic studies published to date. Their findings propose that there is a spectrum of vaginal microbiome states linked to risk for preterm birth (PTB), and that these states vary across populations. They have discovered there are significant racioethnic contributions to PTB, often due to genomic and environmental factors such as socioeconomic status.
These new papers suggest that vaginal microbiome composition in early pregnancy may be the most useful prediction of adverse pregnancy outcomes. Environmental factors, such as our microbiome, is the most significant contributors to PTB. Research is showing that the upwards movement of bacterial microbes from the lower vagina to the placenta, baby and uterus, and oral bacteria transferred from the mouth via our blood, may be the reason why up to 40–50% of preterm births that are associated with microbial causes.
Whilst further studies are needed to examine whether the observed differences in vaginal microbiome composition between women of different ancestries has a direct causal link to the ethnic and racial disparities in PTB rates, the data reported suggests that, when evaluated with other clinical and possibly genetic factors, microbiome-associated taxonomic, metabolic and immunologic biomarkers, once day clinicians may be able to define the risk of PTB, and that this risk might be determined early in pregnancy.
Above articles available via Nature Open Access
1. Jennifer M. Fettweis, Myrna G. Serrano, […] Gregory A. Buck (2019). The vaginal microbiome and preterm birth. Nature Medicine, vol 25, pp 1012–1021.
2. Myrna G. Serrano, Hardik I. Parikh, […] Gregory A. Buck. (2019). Racioethnic diversity in the dynamics of the vaginal microbiome during pregnancy. Nature Medicine, vol 25, pp1001–1011