What ascending infection is linked to a higher incidence of spontaneous preterm birth?

Bacterial vaginosis is indeed linked to a higher incidence of spontaneous preterm birth due to its impact on the vaginal flora and the associated inflammatory response. This condition often leads to an imbalance in normal bacterial populations, resulting in an increased susceptibility to ascending infections.

When bacterial vaginosis is present, pathogenic bacteria can ascend from the vagina into the uterus, which can trigger inflammatory pathways. This inflammation may lead to uterine contractions and cervical changes, both of which are precursors to preterm labor.

In contrast, while other infections like herpes simplex virus or human papillomavirus can have serious implications for maternal and fetal health, they are not primarily associated with the same pattern of ascending infection leading directly to spontaneous preterm birth. Trichomonas may also be linked to poor pregnancy outcomes, but the association with spontaneous preterm birth is not as established as it is for bacterial vaginosis. Thus, bacterial vaginosis is recognized as a significant risk factor for preterm birth due to its direct effect on the uterine environment and the inflammatory processes involved.