Italian scientists recently compared two types of contraceptives – birth control pills and vaginal rings – in terms of clitoral vascularization and sexual behavior in the women who use them. They reported their findings last month in the Journal of Sexual Medicine.
Oral contraceptives have been used for over fifty years and are now the most widely prescribed form of birth control. However, they are known to have side effects involving mood and sex drive. Introduced in 2000, the vaginal ring is a much newer method. Past studies on its sexual side effects have had mixed results.
For this study, the researchers set out to compare the genital vascular effects of the most common form of oral contraceptive and the vaginal ring. They also wanted to learn more about how these methods affected sexual behavior and circulating hormones.
Forty-three Italian women participated in this study. They were between the ages of 18 and 35 years, had normal menstrual cycles, and had been in a stable heterosexual relationship for at least a year. All of the women had body mass indexes that fell into the normal range. None of them had had hormonal therapy or used hormonal contraceptives for at least six months before the start of the study.
Sonograms were used to assess clitoral anatomy and vascularization. The researchers also measured each woman’s levels of estradiol, androstenedione, testosterone, and sex hormone-binding globulin (SHBG). The free androgen index and free estrogen index were calculated for all participants.
The women completed two questionnaires as well. The McCoy Female Sexuality Questionnaire (MFSQ) was used to determine whether the women had sexual dysfunction or not, based on responses to questions in two domains: sexuality and partnership. The Beck Depression Inventory was also administered to evaluate depressive symptoms.
The women were then randomly assigned to one of two treatment groups. One groups took oral contraceptives (Yasmin, which contains drospirenone and ethinyl estradiol. The other used a contraceptive vaginal ring (NuvaRing). Treatment lasted for six months. Assessments were taken at baseline and at the end of the study. Data from forty women were available for analysis.
The researchers found that after six months, testosterone levels had decreased in both groups. Estradiol levels significantly decreased in women taking oral contraceptives, but not in those using the vaginal ring. SHBG levels increased in both groups. The free androgen and free estrogen indexes decreased in both groups, but this decrease was more prominent among women taking oral contraceptives.
When compared to baseline readings, clitoral volume was significantly reduced in both groups, with a larger decrease among women who used the vaginal ring.
While none of the women had sexual dysfunction, both groups saw declines in their MFSQ scores when compared to baseline. However, the oral contraceptive users saw the greater reductions. This group also reported decreases in intercourse frequency and orgasm and an increase in pain during sex.
The women who used vaginal rings experienced mild to moderate vaginal wetness and reported no pain during intercourse.
The authors noted that a number of factors – including physical, social, and psychological ones – can affect a woman’s sexual experience as she uses hormonal contraceptives. They wrote that these factors “require further, broader, and prospective studies to better understand the relationship between hormonal contraception and female sexuality.”
Resources
The Journal of Sexual Medicine
Battaglia, Cesare, MD, PhD, et al.
“Clitoral Vascularization and Sexual Behavior in Young Patients Treated with Drospirenone–Ethinyl Estradiol or Contraceptive Vaginal Ring: A Prospective, Randomized, Pilot Study”
(Full-text. First published online: December 2, 2013)
http://onlinelibrary.wiley.com/doi/10.1111/jsm.12392/full