NEW YORK (12 August 2015)—A study published today in PLOS ONE assessed effects of the Population Council’s investigational one-year reusable contraceptive vaginal ring (CVR) on the incidence of vaginal infections and vaginal microflora. The study demonstrated that use of the CVR for up to 13 cycles presented no increased risk of infection, nor did it disrupt the balance of microbes in the vagina.
The one-year reusable CVR contains Nestorone® and ethinyl estradiol. Nestorone (NES) is an investigational progestin that has been shown in clinical studies to prevent ovulation and pregnancy. Ethinyl estradiol (EE) is an approved, marketed, synthetic version of the female hormone estrogen.
The Population Council’s goal is to offer a safe, effective, acceptable long-acting user-controlled reversible contraceptive that can be inserted and removed by the woman herself rather than by specially trained health care providers, does not require daily action, and can be reused up to one year (13 cycles). It is designed so that refrigeration is not required. Such features may improve overall method adherence and address access and service-delivery issues, especially in low-resource settings where health resources are limited and the unmet need for contraception remains high. In addition to assessing the overall safety, efficacy, and acceptability of this novel CVR, effects of cyclic use of a single vaginal ring used repeatedly for a full year warranted evaluation, specifically its impact on the incidence of vaginal infections and the vaginal microbiota.
The study, “Effects of a one year reusable contraceptive vaginal ring on vaginal microflora and the risk of vaginal infection: An open-label prospective evaluation,” was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) of the National Institutes of Health. The study protocol was approved by the Institutional Review Boards of the NICHD Coordinating Center, the Population Council, and the University of Pittsburgh. All participants provided informed consent.
In this study, researchers assessed the occurrence of common vaginal infections, specifically bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis, in 120 women who used a single NES/EE CVR cyclically over a one-year period. They also evaluated changes in the vaginal microbes of these women.
The researchers found that the NES/EE CVR did not increase risk of vaginal infections or disrupt the balance of microbes in the vagina. They also found that the prevalence of typical vaginal infections in the study population was comparable to the overall prevalence of infections among women of reproductive age. In addition, the researchers took cultures from the surface of the vaginal rings themselves and found that the microbes living on the rings were similar to those in the vaginal fluid.
“We found no substantial effects of long-term repeated use of this novel CVR on the vaginal ecosystem when used for up to 13 cycles, and no significant change on the incidence of vaginal infections,” said Sharon L. Hillier, PhD, Professor of the Department of Obstetrics, Gynecology and Reproductive Sciences, Division of Infectious Diseases and Immunology and Department of Microbiology and Molecular Genetics, at the University of Pittsburgh and the Magee-Womens Research Institute in Pittsburgh, where the study took place.
“This important finding suggests that the NES/EE CVR can be used repeatedly for up to one year without promoting the growth of microorganisms,” said Mitchell D. Creinin, MD, the study’s principal investigator. “The development of a contraceptive vaginal ring that is reusable for a year is a bold move forward for women in developing and developed countries, and I am proud to have contributed to a trial for a novel product with the potential to benefit women and their families all over the world.”
“Several features of the ring make it particularly well-suited to use in low-resource settings where there is a high unmet need for contraception and a high rate of unintended pregnancies. It can be inserted and removed by the woman herself; it does not require daily action; it can be reused for a full year. Also, it does not need to be refrigerated,” said researcher Yongmei Huang, PhD. “As a physician and scientist from a developing country, I know that the NES/EE CVR will greatly benefit women and couples around the world.”
“The strengths of this study are its prospective design and duration,” said Diana L. Blithe, PhD, Director for the Contraceptive Development Research Centers Program of the NICHD. “Past studies of contraceptive vaginal rings have focused only on short-term usage.”
“The results of this study will be valuable in our efforts to gain regulatory approval for this novel contraceptive that is under the control of women. It has the potential to be an important addition to the available contraceptive method mix,” said Ruth Merkatz, PhD, Director, Clinical Development, Center for Biomedical Research at the Population Council. “We are grateful for the support we have received from NICHD to conduct this study and for ongoing support for development of the NES/EE CVR from the US Agency for International Development (USAID), the Bill and Melinda Gates Foundation, and the World Health Organization.”
The Population Council has a long history of developing long-acting, reversible contraceptives to meet the growing worldwide demand for modern family planning methods. Council-developed contraceptive products include the copper-T intrauterine device (IUD), the levonorgestrel intrauterine system known as Mirena®, and the implants Jadelle® and Norplant®. Currently, 170 million women worldwide are using a Council-developed contraceptive.
Article citation: Huang, Yongmei, Ruth B. Merkatz, Sharon L. Hillier Kevin Roberts, Diana L. Blithe, Régine Sitruk-Ware, and Mitchell D. Creinin. 2015. “Effects of a one year reusable contraceptive vaginal ring on vaginal microflora and the risk of vaginal infection: An open-label prospective evaluation,” PLOS ONE 10(8): e0134460. doi:10.1371/journal.pone.0134460.
About the Population Council
The Population Council confronts critical health and development issues—from stopping the spread of HIV to improving reproductive health and ensuring that young people lead full and productive lives. Through biomedical, social science, and public health research in 50 countries, we work with our partners to deliver solutions that lead to more effective policies, programs, and technologies that improve lives around the world. Established in 1952 and headquartered in New York, the Council is a nongovernmental, nonprofit organization governed by an international board of trustees.
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