Changes In Vaginal Flora During Pregnancy And Association With Preterm Birth

Abstract

A prospective study of the vaginal flora changes between midtrimester and labor was undertaken in 560 women; 337 had intact membranes and were in labor when swabs were taken. Of these, 45 delivered preterm. Gardnerella vaginalis, Ureaplasma urealyticum (both associated with preterm birth when present in midtrimester), and Mycoplasma hominis commonly persisted between midtrimester and labor, particularly in the preterm cohort (24 [65%] of 37 midtrimester isolates), and these organisms were seldom acquired late in pregnancy. A second group, Bacteroides species, had both a high persistence (9 [60%] of 15 midtrimester isolates) and high late acquisition rate (10 [53%] of 19 labor isolates) in the preterm cohort. These findings provide a rationale for treatment of bacterial vaginosis in pregnancy. A third group, comprising enteropharyngeal bacteria and Peptostreptococcus species, were almost all acquired late in the preterm cohort (14 [88%] of 16 labor isolates), and persistence from midtrimester was rare.

Definition of a type of abnormal vaginal flora that is distinct from bacterial vaginosis: aerobic vaginitis

“…Severe complications such as mid-trimester pregnancy losses, chorioamnionitis and even first trimester abortions were linked to the latter flora and mycoplasmata 8,17,18 . McDonald et al 9 found E. coli and group B streptococci to be important pathogens alongside the classical bacterial vaginosis organisms, and we reported that abnormal flora, but not full-blown bacterial vaginosis, was associated with preterm birth 11,19 . We hence suggested that a second abnormality of the vaginal flora should be considered, now termed 'aerobic vaginitis' 1 .…”

“…No AV Mild AV Moderate / severe AV BV other 8,9 . Severe complications such as mid-trimester pregnancy losses, chorioamnionitis and even first trimester abortions were linked to the latter flora and mycoplasmata 8,17,18 .…”

“…The inability of the Nugent score to pick up cases with aerobic vaginitis, therefore, hampers the validity of its use in treatment trials and in studies trying to predict and prevent preterm delivery and other adverse pregnancy outcome. Aerobic vaginitis typically does not respond to anti-bacterial vaginosis medication, perhaps explaining why studies using metronidazole failed to show adequate cure in about 15% of cases of bacterial vaginosis and not even 50% in cases with intermediate flora according to Nugent 9,10 .…”

Ipomoea imperati (Vahl) Griseb. (Convolvulaceae): nuevo xenófito invasor en la provincia de Cádiz (Sur de España)

“…Es exclusiva de arenales costeros, donde crece formando densos tapices (McDonald, 1994;Silvestre, 2012). Los tallos son glabros y pueden alcanzar los 10 m de longitud y 2-7 mm de diámetro.…”

A study of aerobic bacterial pathogens associated with vaginitis in reproductive age group women (15-45 years) and their sensitivity pattern

“…Such forms of abnormal flora have been termed 'intermediate flora' in some studies, or been included with full-blown bacterial vaginosis in others. [4][5][6] This type of undefined abnormal flora may be of crucial importance in pregnant women at risk of preterm delivery. 4,6 Therefore, now it has been clear that the classifications of Candida vaginitis, Trichomonas vaginitis, and Bacterial vaginosis are insufficient to explain all clinical symptoms, therapy failures and the surprising outcomes of some studies on the link between some forms of bacterial flora and preterm birth rate.…”