PARK CITY, UTAH – Copper IUDs really do increase the risk of bacterial vaginosis (BV), according to a longitudinal study of 234 women in Harare, Zimbabwe.
This notion has “always been a little bit controversial; it’s commonly believed by some and refuted by others,” but the findings from the new research “are real and generalizable,” said Sharon Hillier, PhD, the study’s senior investigator and the director of reproductive infectious disease research at Magee-Womens Hospital of the University of Pittsburgh.
Dr. Sharon Hillier
The African women in this study were all free of HIV and sexually transmitted infections; on average, they were about 26 years old; and most were married and sexually active. As part of a larger look into the role of vaginal dysbiosis in HIV acquisition, they were given five options for contraception: three kinds of injectables; one implant; and the nonhormonal copper IUD.
The women were divided almost evenly among the five options. The researchers followed them for 6 months with routine vaginal swabs and polymerase chain reaction testing during the follicular phase of menses. Women who opted for the copper IUD were slightly less likely to report being married and sexually active.
Almost a third of the women had BV at baseline, a little higher than the prevalence in American women.
Women who opted for hormonal contraceptives had no change in BV prevalence or vaginal microbiota.
However, BV prevalence in women who opted for the copper IUD increased from 27% at baseline to 34% at 30 days, 39% at 90 days, and 44% at 180 days. There was an increase in concentrations of Gardnerella vaginalis and Atopobium vaginae that was not seen in the hormonal contraception groups. Overall, copper IUDs showed a twofold increase in the relative risk of BV.
“I don’t think there’s anything here that’s particularly alarming. This would not dissuade me from recommending a copper IUD. It’s a very effective and safe nonhormonal way of having long-acting reversible contraception, but if a woman gets a copper IUD and she has recurrent BV, you need to understand that the IUD may be playing a role,” Dr. Hillier said in an interview at the annual scientific meeting of the Infectious Diseases Society for Obstetrics and Gynecology.
The increased risk is probably because IUDs cause heavier and longer menstrual bleeding, which is known to disturb the vaginal microbiome. Work is underway to see if removing the IUD reverses the effects, Dr. Hillier said.
Most of the women in the study opted to keep their IUDs in place after 6 months.
The Gates Foundation supported the work. Dr. Hillier is a consultant for Merck and Symbiomix and a researcher for Becton Dickinson and Cepheid.