Thirteen studies were reported in some detail (the total number of participants was not given). One of these studies used the antibacterial drug metronidazole. Other studies were referred to but no details were reported.
Three studies measured microbiological outcomes: one study (numbers not stated) followed quantitative and qualitative changes in bacterial counts, while the other 2 studies measured the total bacterial counts at single time points.
Ten studies measured clinical outcomes: there were 2 studies (n=251) of infectious morbidity, 3 studies (numbers not stated) of febrile morbidity, and 2 studies (n=345) of both infectious and febrile morbidity; no outcomes were reported for the other 3 studies (numbers not stated).
Studies reporting bacteriological outcomes.
One study found that, for quantitative bacterial counts of vaginal aspirates taken right after the preparation, chlorhexidine 0.05% was relatively ineffective, whilst povidone-iodine diluted 1/10 and chlorhexidine 0.015%-cetrimide 0.15% were quite effective. Another study found that povidone-iodine was the most effective agent when compared with chlorhexidine and normal saline. A further study measured comparative vaginal aerobic and anaerobic bacterial counts intermittently, several hours after the application of the povidone-iodide liquid or gel. After vaginal painting with the liquid, a dramatic initial fall in bacterial counts was followed by recovery to near baseline levels within 30 minutes. After vaginal application of the gel, effective bacterial action was documented over a 3-hour period with gradual recovery of bacterial counts.
Studies reporting clinical outcomes.
A small study (n=33) found no difference in febrile morbidity between women given two povidone-iodide douches and a povidone-iodine scrub and those give saline equivalents. In another study, the overall infectious morbidity was less in women having a povidone-iodine scrub and soaked tampon (14 out of 51 women) than in those who had no vaginal preparation (26 out of 45 women) (p<0.01). A further study compared four different vaginal antiseptics: 2 chlorhexidine douches or 2 povidone-iodine douches or 2 povidone-iodine douches with povidone-iodine gel the day previously or no douche. This study found that there were significant differences in total infectious morbidity among the four groups, with lower rates found in the povidone-iodine groups. A study of povidone-iodine pessaries plus povidone-iodine solution versus chlorhexidine 0.015%-cetrimide 0.15% found that infection (at any site) was diagnosed in 34 of the 51 women in the povidone-iodine group, and in 34 of the 52 women in the other group; antibiotic treatment directed at vault infection was used in 12 and 7 of the women, respectively. A further study found that for the outcomes of febrile mortality and prolonged febrile mortality, iodine vaginal gel was more effective than the standard treatment (historical controls).