Influence of Modifiable Factors on the Vaginal Microbiota and Preterm Birth

描述（由申请人提供）：早产（PTB）是婴儿死亡的主要原因，每年造成数十亿美元的可避免的健康费用。早产的原因尚不清楚，但被认为是由复杂的人口、生物和行为因素引起的。最近，阴道生态失调——阴道微生物群的破坏——已被证明与肺结核有关。研究还表明，阴道微生物群失调的组成、频率和持续时间可能受到已知早产预测因素的人口统计学、生物学和行为因素的影响。这项拟议的研究将检查已知与肺结核相关的社会和生物行为因素对阴道微生物群组成以及阴道生态失调的频率和持续时间的贡献。本研究的总体目标是阐明社会和生物行为因素、阴道微生物群与分娩妊娠之间的关系。具体目标包括描述社会和生物行为因素对出生妊娠的影响（目的）

DESCRIPTION (provided by applicant): Preterm birth (PTB) is the leading cause of infant mortality and incurs billions of dollars per year in avoidable health costs. The causes of preterm birth are not well understood but are thought to originate from complex demographic, biological and behavioral factors. More recently vaginal dysbiosis - disruptions in the vaginal microbiota - have been shown to be associated with PTB. Studies have also shown that the composition and the frequency and duration of dysbiosis in the vaginal microbiota may be affected by the same demographic, biological and behavioral factors that are known predictors of preterm birth. This proposed study will examine the contribution that social and bio-behavioral factors known to be associated with PTB have on the composition of the vaginal microbiota as well as the frequency and duration of vaginal dysbiosis. The overall goal of this study is to elucidate the relationship between social and bio-behavioral factors, the vaginal microbiota and birth gestation. Specific aims include characterizing the effect of social and bio-behavioral factors on birth gestation (Aim 1) and on the vaginal microbiota (Aim 3), characterizing the effect of the microbiota on birth gestation (Aim 2) and quantifying the role of the vaginal microbiota in the relationship between social and bio-behavioral factors and birth gestation (Aim 4). In this prospective cohort study, 400 women will be followed from 20 weeks gestation through to birth. By recruiting pregnant women from neighborhoods in Baltimore City with higher than average PTB rates we expect that at least 16% of the cohort will experience premature birth. Weekly self-collected mid-level vaginal swabs will be obtained using a validated protocol. Diet information, vaginal and prenatal health behavior data will be collected via a web- based application specifically designed for this study. Structural equation modeling and mixed effects models will be used to test the hypotheses. The sample for Aims 1, 3, and 4 will include the full cohort while Aims 2-4 will use a subsample of cases that deliver preterm and age-matched controls. Vaginal swabs and pH for the women that experience PTB and the age-matched control will be analyzed using r16S culture-independent techniques. Findings will provide essential knowledge about the influence that modifiable social and bio- behavioral factors have on the composition and frequency and duration of vaginal dysbiosis during pregnancy the PTB.