Which organism is associated with vertically transmitted infections in pregnant women at risk for complications during delivery?

The organism associated with vertically transmitted infections in pregnant women, particularly linked to complications during delivery, is Listeria monocytogenes. This bacterium is known for its ability to cross the placental barrier and can lead to serious infections in the fetus, including miscarriage, stillbirth, or severe neonatal illness such as sepsis and meningitis.

Listeria monocytogenes is often contracted through contaminated food products, which is particularly concerning for pregnant women who need to be vigilant about their dietary choices. The pathogenicity of Listeria in pregnancy underscores the importance of proper food-handling practices and awareness of the risks associated with certain foods.

In contrast, other organisms like Streptococcus agalactiae, while also significant in the context of pregnancy, primarily cause infections during and after delivery rather than through vertical transmission in the same way as Listeria. Escherichia coli is often responsible for urinary tract infections and other infections, but it does not have the same direct link to vertical transmission as Listeria. Neisseria meningitidis, although it can cause severe infections, is primarily transmitted through respiratory droplets and not typically associated with vertical transmission from mother to fetus. Thus, Listeria monocytogenes stands out as