Early Pregnancy Changes in Bacterial Vaginosis‐Associated Bacteria and Preterm Delivery

Abstract

Background We evaluated the importance of measuring early vaginal levels of eight BV-associated bacteria, at two points in pregnancy, and the risk of spontaneous preterm delivery (SPTD) among pregnant women and the subgroup of pregnant women with a history of preterm delivery (PTD). Methods This prospective cohort study enrolled women at five urban obstetric practices at Temple University Hospital in Philadelphia PA. Women with singleton pregnancies less than 16 weeks gestation self-collected vaginal swabs at two points in pregnancy, prior to 16 weeks gestation and between 20-24 weeks gestation, to measure the presence and level of eight BV-associated bacteria. Women were followed-up for gestational age at delivery via medical records. Results Among women reporting a prior PTD, women with higher levels of Leptotrichia/Sneathia species, BVAB1 and Mobiluncus spp., prior to 16 weeks gestation, were significantly more likely to experience a SPTD. In addition, pregnant women with a prior PTD and increasing levels of Leptotrichia/Sneathia species (aOR: 9.1, 95% CI: 1.9-42.9), BVAB1 (aOR: 16.4, 95% CI: 4.3-62.7) or Megasphaera phylotype 1 (aOR: 6.2, 95% CI: 1.9-20.6), through 24 weeks gestation, were significantly more likely to experience a SPTD. Among the overall group of pregnant women, the levels of BV-associated bacteria were not related to SPTD. Conclusion Among the group of women reporting a prior PTD, increasing levels of BVAB1, Leptotrichia/Sneathia species, and Megasphaera phylotype 1, through mid-pregnancy were related to an increased risk of SPTD.

The Changing Landscape of the Vaginal Microbiome

“…As outlined above, this observation is also consistent with the fact that BV is a recurrent if not chronic problem for many women. A recent study reported that, among women with a history of PTB, women with high levels of Sneathia species, BVAB1 and Mobiluncus species early in pregnancy, were significantly more likely to experience a spontaneous PTB 94 . We recently reported that the genome of a Sneathia amnii strain from a woman who experienced preterm birth bears various potential pathogenic determinants including cytotoxins and adhesins.…”

High Diversity and Variability in the Vaginal Microbiome in Women following Preterm Premature Rupture of Membranes (PPROM): A Prospective Cohort Study

“…and Mycoplasma spp. in the vaginal microbiomes of women who deliver preterm [20, 21]. To date there has been no comprehensive study, utilizing high-throughput gene sequencing based methodologies, to characterize the microbiome in the context of preterm premature rupture of the membranes.…”

Relationship of Specific Bacteria in the Cervical and Vaginal Microbiotas With Cervicitis

“…Detection of fastidious urogenital bacterial species with quantitative PCR (qPCR) has been associated with preterm birth 15 , persistent BV 16 , and urethritis in men 17 . Here we applied this methodology to investigate the relationship of eight BV-associated bacterial species/genera and three of the most common vaginal lactobacilli with cervicitis in a retrospective case control study of women attending a Seattle STD clinic.…”