Bacterial vaginosis (BV) is a condition in which the normal hydrogen peroxide producing lactobacilli in the vagina are depleted, resulting in an overgrowth of anaerobic bacteria, Gardnerella, and Mycoplasma. In other words, the good bacteria (which are the gate keepers and control the vaginal ecosystem) are replaced by the bad bacteria.
BV causes an annoying, irritating discharge with a fishy odor, but beyond the troublesome symptoms bacterial vaginosis is also associated with an increase acquisition rate of sexually transmitted infections (STIs) if exposed. This is because low counts of lactobacilli mean a reduction in an important first line of defense against pathogens such as gonorrhea and HIV.
Bacterial vaginosis has a high recurrence rate, which in not only frustrating but is worrisome from an SIT standpoint (BV also increases the risk of infection after a c-section, an abortion, and hysterectomy). Twenty to forty percent of women will have a recurrence of BV within 3 months of treatment and in some studies up to 80% will have a recurrence by 9 months, so not great odds.
The problem with pharmaceutical treatments for BV is that while they knock out the bad bacteria (hence treating the discharge and odor) they do nothing to encourage the regrowth of the good bacteria. And while some studies suggest specific probiotics can be helpful, in my experience adding in the right probiotic is not usually enough.
For many years I have advocated condoms as part of the treatment of recurrent BV, based on studies that tell us that BV is almost unheard of in virginal women, that introduction of a new partner more than doubles the risk of BV, and that barrier contraception may slightly reduce the risk of BV. Many years ago I heard a leading microbiologist talk about ejaculate affecting lactobacilli counts, and that certainly makes sense if you think about the fact that virginal women almost never get BV and that a new sexual partner increases the risk.
A new study lends further credence to the condoms for BV prevention theory. Investigators in China looked at hydrogen peroxide producing lactobacilli (the most important kind as far as BV and STI prevention are concerned) and found that colony counts of the good bacteria were higher among condom users versus those who used the copper IUD or the rhythm method. The effect was most pronounced for L. crispatus, one of the strongest H2O2-producing Lactobacilli.
While the study did sample women at the same time of the menstrual cycle there is a significant flaw in that some very important demographic data was not addressed, specifically the number of episodes of coitus and the number of distinct male sexual partners. If more women using a copper IUD had multiple partners and/or had more episodes of coitus that could easily explain the difference and the effect would not be from condoms. All the women were married, but that tells us nothing about coital frequency or number of other partners. Even more concerning this missing demographic data wasn’t even addressed in the discussion. This is something a reviewer should have picked up and insisted it be addressed in some way.
Regardless, this study does add some more credence to the theory that there’s something in ejaculate besides STIs that can be harmful to the female genital tract and if a woman has recurrent bacterial vaginosis using condoms (no spermicide, as that kills lactobacilli) while she is on a maintenance treatment for BV can be a useful strategy. In my clinical experience, using the right induction and suppressive regimen coupled with condoms and a few other tricks is highly effective for recurrent BV.