Sialidase and β-N-acetyl-hexosaminidase are significantly increased in BV [3], and increased sialidase and/or prolidase activity is associated with preterm birth, premature rupture of membranes, low birth weight and very low birth weight [3, 4, 59–62] when combined with vaginal pH > 5 [45]. Here, PEPD is linked to bacterial vaginosis.