Study: post-BV-treatment sex life and contraceptives use matters

A study[1. Recurrence of bacterial vaginosis is significantly associated with posttreatment sexual activities and hormonal contraceptive use, Bradshaw C.S, Vodstrcil L.A, Hocking J.S, De Guingand D, Fairley C.K, Pirotta M, Garland S.M, Morton A.N, Law M, Clinical Infectious Diseases-6-56(2013)] looked into sexual practices and hormonal contraceptives use after treatment for bacterial vaginosis.

Because BV recurrence is so common after antibiotic treatment, the researchers wanted to know what – if anything – was contributing to holding the treatment back.

The study into post-BV sex and contraceptives

A randomised controlled trial that involved women with BV symptoms, aged between 18 and 50, at a Melbourne Sexual Health Centre (Australia). All 450 participants received oral metronidazole for seven days, and were randomised to receive vaginal clindamycin, lactobacillus-vaginal probiotic, or a vaginal placebo.

Results of the study

At each milestone (one, two, three and six months respectively), participants collected vaginal smears and completed questionnaires. Cumulative six-month recurrence was 28 per cent and not associated with treatment. After adjustments were made, recurrence was associated with having the same pre- and post-treatment sex partner, inconsistent condom use, and being from somewhere other than Australia. Recurrence rates halved in those using an oestrogen-containing contraceptive.

Conclusions of the study

Risk of BV recurrence was increased when women had the same partner before and after treatment and didn’t use condoms, but oestrogen-based birth control appears to provide a protective effect.

What we think

This study illustrates the sexually transmissible nature of BV, and the importance of treating a sexual partner and using condoms until the infection has resolved completely in both partners.

This is harder said than done, due to the biofilm nature of BV which can cling to the urethra and penis in men for weeks and months after contact. This was particularly prevalent in men who had a female sexual partner (typically a long-term partner) they did not use condoms with.

Read more about the sexual transmission of BV here to get the full picture. 

Oestrogen-based hormonal birth control was been shown to have a somewhat protective effect on BV, possibly because it provides vaginal lactobacilli with a consistent source of glycogen. Oestrogen stimulates the production of glycogen in the vagina, which feeds lactobacilli.