Scientists detect proteins, bacteria in vagina to identify women at risk of premature birth
Researchers plan to create a low-cost diagnostic to identify these risk factors among women in resource-poor countries
More than one in 10 babies are born too early every year and an approximately one million children die each year due to complications of preterm birth.
Scientists have now found components in the vagina - proteins and bacteria - that can be used to identify women who are at high risk of premature birth. They are in the process of planning and creating an inexpensive point-of-care diagnostic to identify and assess the presence of risk factors for preterm births among women in resource-poor countries.
"We have found that there are components in the vagina that can be used to identify women who are at elevated risk of preterm birth," says Dr Larry Forney, a member of the Institute of Bioinformatics and Evolutionary Studies and distinguished university professor in the Department of Biological Sciences, University of Idaho, Moscow, Idaho.
The World Health Organization (WHO) defines preterm as babies born alive before 37 weeks of pregnancy.
The aim of the research, says the team, is to develop a diagnostic that people can use in a clinic that does not require any advanced technology, expensive instrumentation, or extremely specialized skills. This, say experts, will ensure intensive monitoring as well as advanced or targeted therapies if needed.
"Currently, vaginal ultrasound and microbiome determination require special expertise and the use of expensive equipment. We envision that a point-of-care kit could be performed by minimally trained personnel, would not need any equipment, and would be much less costly. Our studies are ongoing. The production of a point-of-care kit is still in the early planning stages," study co-author Dr Steven Witkin from the Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, US, told MEA WorldWide (MEAWW).
"If you can identify people at risk, there are standard therapies that can be given. But if you do not know who is at risk, then you cannot have a basis of choosing who should receive the additional therapy," says Dr Witkin.
According to the WHO, every year, an estimated 15 million babies are born preterm and this number is rising. Across 184 countries, the rate of preterm birth ranges from 5% to 18% of babies born. Preterm birth complications are the leading cause of death among children under five years. The WHO further says three quarters of these deaths could be prevented with cost-effective interventions.
Doctors have known for years that a short cervical length and depletion of Lactobacillus species in the vaginal microbiome are significant risk factors for premature birth.
"In prosperous countries, most pregnant women undergo a transvaginal ultrasound at 18 to 24 weeks gestation, to determine cervical length, and women with a short cervix are treated with progesterone, a cerclage, or a cervical pessary, to reduce the likelihood of premature delivery. Similarly, women who show signs of bacterial vaginosis (an abnormal vaginal condition) are given antibiotics to restore the dominance of lactobacilli and reduce the risk of preterm birth," says the study published in mBio, an open-access journal of the American Society for Microbiology.
However, the resources to conduct a transvaginal ultrasound or characterize the composition of vaginal bacterial communities are unavailable in poorer countries, says the team.
For the study, the researchers collected and analyzed vaginal fluid samples from 340 mid-trimester pregnant women to determine the 'correlates' of a short cervix. Roughly 10% of women in the study had a short cervix.
The research team found that measuring levels of TIMP-1 and D-lactic acid in vaginal secretions might be a non-invasive, cost-effective way to evaluate the risk for preterm birth due to a "short cervix and microbiome composition." According to them, a low-cost diagnostic kit could be used to predict bacteria that dominate the vaginal microbiome and indicate the presence of a shortened cervix.
"Tissue inhibitor of matrix metalloproteinases (TIMP-1), D-lactic acid, p62, age, and race all directly affected cervical length," says the study.
According to the researchers, the next step is to do a larger study that includes women in their first trimester so that if the findings are similar, monitoring and possible treatment can begin earlier in gestation.
"If a simple point-of-care kit becomes available to assay D- and L-lactic acid and TIMP1 in pregnant women, it could triage the extent and the type of care and monitoring needed during pregnancy," Dr Witkin told MEAWW.