The Depo Provera and BV – help or hindrance?

The Depo Provera shot may act as a barrier to the successful treatment of bacterial vaginosis (BV), despite earlier research indicating this type of birth control may have a protective effect on BV relapse.

The contraceptive shot has been shown to somewhat reduce lactobacilli numbers in the vagina (with diversity of other species increasing) and cause a slight thinning of the epithelial cells. This is bad news when it comes to treating BV. You need low diversity in species, lactobacilli in solid numbers, and thick, healthy epithelial cells, your best and first defence against intruders.

Depot medroxyprogesterone acetate (DMPA), the depo shot, is a three-monthly hormonal injected contraception. The shot is already known to come with an increased risk of HIV acquisition, which is possibly related to alterations in the vaginal microbiome and impact on the epithelium.

The contraceptive shot causes a state of low oestrogen throughout the body at a time when fertility and sexual activity are at their peak. This decrease in oestrogen can result in a loss of important protective mechanisms, resulting in an increase in infections and the application of repeated, ineffective treatments.

Vaginal oestrogen creams have been proposed as an aid for those who use the shot as the best option for birth control. Other options include stopping using it and opting for less problematic birth control.

Why oestrogen matters to your vagina

Oestrogen is important in a healthy vagina for many reasons, but when it comes to BV, oestrogen stimulates glycogen production in epithelial cells (the top layer).

This glycogen, in turn, feeds healthy flora, lactobacilli. Oestrogen also keeps vaginal epithelial cells plump and healthy, supporting innate immunity.

What does the shot (low oestrogen) do in the vagina?

While no significant disruptions to vaginal flora have been observed, slight changes in diversity and species can make all the difference when it comes to problems; a chink in the armour, if you like.

Microbial diversity in the vagina is associated with an increase in infections, while, for example, diversity in the digestive tract is associated with a healthy gut. We just want a small handful of healthy microbes in the vagina.

The depo shot, in one study in women of colour in the United States (those of African and Hispanic descent), found that vaginosis-associated bacteria were increased at the second visit. Vaginal microbial diversity increased after the injection.

Black women fared worse in terms of diversity than Hispanics of European descent (white Hispanics), which matches other studies into the microbiome around the world.

Why does ethnicity matter when it comes to the vagina?

We inherit our vaginal microbiome from our birth mothers. This passing on of microbes occurs during and after birth.

Those of African descent have, by nature, greater vaginal microbial diversity and fewer lactobacilli, which means black women get more BV. A handful of solid vaginal warriors is all we need to get by, with lactobacilli species being largely an Asian and European thing.

References

Miller L, Patton DL, Meier A, Thwin SS, Hooton TM, Eschenbach DA. Depomedroxyprogesterone-induced hypoestrogenism and changes in vaginal flora and epithelium. Obstet Gynecol. 2000;96(3):431‐439. doi:10.1016/s0029-7844(00)00906-6

Martha Hickey, BA(Hons), MSc, MBChB, FRCOG, FRANZCOG, MD, Jennifer L. Marino, MPH, PhD, and Gilda Tachedjian, BSc(Hons), PhD. Mechanisms of HIV Transmission in Depo-Provera: The Likely Role of Hypoestrogenism. J Acquir Immune Defic Syndr 2016;71:1–7

Caroline M. Mitchell, Leslie McLemore, Katharine Westerberg, Rena Astronomo, Kimberly Smythe, Carolyn Gardella, Matthias Mack, Amalia Magaret, Dorothy Patton, Kathy Agnew, M. Juliana McElrath, Florian Hladik, David Eschenbach, Long-term Effect of Depot Medroxyprogesterone Acetate on Vaginal Microbiota, Epithelial Thickness and HIV Target Cells, The Journal of Infectious Diseases, Volume 210, Issue 4, 15 August 2014, Pages 651–655

Yang L, Hao Y, Hu J, et al. Differential effects of depot medroxyprogesterone acetate administration on vaginal microbiome in Hispanic White and Black women. Emerg Microbes Infect. 2019;8(1):197‐210. doi:10.1080/22221751.2018.1563458