A longitudinal study of bacterial vaginosis during pregnancy

Abstract

Objective To determine the longitudinal changes in the incidence of bacterial vaginosis in pregnancy. Design A prospective study of women during pregnancy. Setting A District General Hospital in North‐West London. Subject Seven hundred and eighteen pregnant women attending antenatal clinics. At their first attendance and subsequently, Gram‐stained vaginal smears were examined and Mycoplasma hominis and Gardnerella vaginalis were sought by culture. Results Initially, 87 (12%) women had bacterial vaginosis diagnosed on Gram‐stained reading of the vaginal smears. Examination of further smears, obtained from 176 women at 36 weeks of gestation, showed that those whose vaginal flora was normal initially, and who went to term, rarely developed vaginosis (three of 127, 2.4%). Samples were obtained at 36 weeks gestation from 32 women who had bacterial vaginosis initially, and went to term. In almost 50% (15 of 32) of these a normal lactobacillus‐dominated flora had regenerated. Thirty‐five women (5%) had initial vaginal smears graded as intermediate. From this group, six of the 17 (35%) women from whom samples were obtained at 36 weeks gestation still had flora of an intermediate pattern; 10 (59%) now had normal flora and only one (6%) had developed bacterial vaginosis. Women with bacterial vaginosis were more likely to be culture‐positive for M. hominis than those with normal flora (34/78 versus 10/563, odds ratio 42.73 (18.9 to 102.3) P < 0.001), or to be culture‐positive for G. vaginalis than those with normal flora (35/78 versus 21/563, odds ratio 21.0 (10.75 to 41.2) P < 0.001). Conclusion Pregnant women do not commonly develop bacterial vaginosis after 16 weeks gestation, and if present, it remits spontaneously in approximately half of those who reach term. As bacterial vaginosis is associated with increased rates of second trimester miscarriage and preterm delivery, any treatment aimed at its eradication in pregnancy should be given no later than the beginning of the second trimester of pregnancy.

Normal flora and bacterial vaginosis in pregnancy: an overview

“…are not related to the risk of pregnancy loss. The risk for adverse outcome is 10-fold increased if women have a history of pregnancy loss (Hay et al, 1994;Guerra et al, 2006). While this is supported by the finding that BV is associated with very preterm delivery (<32 weeks gestation) (Goffinet et al, 2003), it is contradicted by other studies that found no association of BV with PTD (Povlsen et al, 2001;Harper et al, 2012).…”

“…The prevalence of BV varies considerably over the course of pregnancy and is suggested to decrease as pregnancy progresses (Hay et al, 1994;Waters et al, 2008;Krauss-Silva et al, 2014). Waters et al (2008) reported that BV is the most prevalent in the first trimester of pregnancy (43.9%) but less prevalent in the second (21.6%) and third trimesters (18.9%).…”

“…It may be directly linked to the spontaneous resolution of up to 27% of BV infections as gestational age progresses (Hay et al, 1994;McDonald et al, 1994;Klebanoff et al, 2004). Although the etiology of recurrent BV is unknown, it has been found that retreatment with the same antimicrobial agent produces a higher cure rate (Bunge et al, 2009).…”

A New Effective, User-friendly Bacterial Vaginosis Treatment: A Randomized Multicenter Open-label Parallel-group Two-part Study with a Novel Sustained-release Pessary Containing Oligomeric Lactic Acid

“…Treatment of BV using antibiotics is often associated with high rates of recurrence even after a proper treatment course which might reflect resistance, recurrence and/or reinfection and/or be a consequence of insufficient pH restoration [7,45]. Intermittent local prophylactic treatments with a lactic acid vaginal gel in women experiencing recurrent BV has been evaluated in a double-blind placebo controlled six month study [20]. That study verifies that a local vaginal lactic acid formulation can be used successfully not only for treatment of acute symptoms, but also prophylactically to restore a normal pH and microflora and to prevent recurrences [41].…”

“…However, it is not known what mechanism(s) causes these adverse pregnancy outcomes [3,[16][17][18][19]. As BV is found in approximately 16% of pregnant women in industrial countries, it poses a serious problem [3,[20][21][22]. Approximately every second woman, both pregnant and non-pregnant, is asymptomatic, thus making treatment even more cumbersome [6].…”