Impact of interconception antibiotics on the endometrial microbial flora

Abstract

Objective-To evaluate the impact of an interconceptional antibiotic regimen on the endometrial microbial flora and histology.Study Design-Secondary analysis of a double-blind randomized placebo-controlled trial of prophylactic metronidazole + azithromycin given to 241 women (118 on antibiotics and 123 on placebo) with a prior preterm delivery to prevent recurrent preterm delivery. Endometrial cultures and histology were obtained at randomization and 2 weeks after treatment. The prevalence of either the new acquisition or the resolution of individual microbes, categories of microbes and plasma cell endometritis were compared using Chi square or Fisher exact tests.Results-Overall, antibiotics were associated with lower acquisition and higher resolution of microbes. Of women without Gardnerella vaginalis at baseline, 14% on antibiotics vs. 34% on placebo had positive endometrial culture for the organism after treatment (p<0.05), while of those with Gardnerella at baseline, 57% vs. 33% (p<0.05) had a negative follow-up culture. Other Gramnegative rods, especially aerobes in general also manifested similar patterns. The impact on anaerobes and plasma cell endometritis was not definitive but there was a trend toward the increased resolution of the former (77% vs. 55%) and reduced acquisition of the latter (28% vs. 50%). Conclusion-The antibiotic regimen prevented acquisition and promoted resolution, but not eradication, of Gram-negative rods such as Gardnerella vaginalis and the aerobic sub-category.

New Opportunities for Endometrial Health by Modifying Uterine Microbial Composition: Present or Future?

“…In many cases, its administration aggravates the underlying dysbiosis in long term and may promote resistance [140]. For instance, prescription of antibiotics in a prophylactical way has not resulted in improved pregnancy outcome not even in the cases of high risk of preterm birth on the presence of pathogens [166].…”

Presence of a Polymicrobial Endometrial Biofilm in Patients with Bacterial Vaginosis

“…Several studies have challenged this view and found high rates of uterine bacterial colonization [10], [12]. These studies may be thought to be due to contamination from the vagina.…”

Colonization of second-trimester placenta parenchyma

“…The Chi-square statistic then tests that the observed occurrence in any cell is unlikely to differ from that expected by chance. With most displays comparing two rows by week of gestation (23,24,25,26,27), a "significant p value" does not inform us about which of the many comparisons within this 2×5 array is what makes the p value significant.…”

“…On the other hand, antibiotics can promote endometrial resolution, but not the eradication, of gram-variable rods such as G. vaginalis, as well as new bacterial acquisitions. 25 More than 80% of 820 endometrium cultures obtained three months after delivery yielded a microorganism. 5 The authors of that study argued that contamination could not account for all that they saw because half of these specimens had plasma cell endometritis, and because the microorganisms recovered did not match the distribution of species in the vagina, the most probable source of the putative contamination.…”