Effectiveness of long-acting reversible contraception

BACKGROUND

The rate of unintended pregnancy in the United States is much higher than in other developed nations. Approximately half of unintended pregnancies are due to contraceptive failure, largely owing to inconsistent or incorrect use.

METHODS

We designed a large prospective cohort study to promote the use of long-acting reversible contraceptive methods as a means of reducing unintended pregnancies in our region. Participants were provided with reversible contraception of their choice at no cost. We compared the rate of failure of long-acting reversible contraception (intrauterine devices [IUDs] and implants) with other commonly prescribed contraceptive methods (oral contraceptive pills, transdermal patch, contraceptive vaginal ring, and depot medroxyprogesterone acetate [DMPA] injection) in the overall cohort and in groups stratified according to age (less than 21 years of age vs. 21 years or older).

RESULTS

Among the 7486 participants included in this analysis, we identified 334 unintended pregnancies. The contraceptive failure rate among participants using pills, patch, or ring was 4.55 per 100 participant-years, as compared with 0.27 among participants using long-acting reversible contraception (hazard ratio after adjustment for age, educational level, and history with respect to unintended pregnancy, 21.8; 95% confidence interval, 13.7 to 34.9). Among participants who used pills, patch, or ring, those who were less than 21 years of age had a risk of unintended pregnancy that was almost twice as high as the risk among older participants. Rates of unintended pregnancy were similarly low among participants using DMPA injection and those using an IUD or implant, regardless of age.

CONCLUSIONS

The effectiveness of long-acting reversible contraception is superior to that of contraceptive pills, patch, or ring and is not altered in adolescents and young women. (Funded by the Susan Thompson Buffet Foundation.).

Continuation and satisfaction of reversible contraception

OBJECTIVE

To estimate 12-month satisfaction and continuation rates of intrauterine device (IUD) and implant users enrolled in the Contraceptive CHOICE Project and compare these measures with women using the oral contraceptive pills (OCPs).

METHODS

We analyzed 12-month data from the first 5,087 participants enrolled in a prospective cohort study of women in the St. Louis region offered contraception at no cost for 3 years. The primary purpose of CHOICE is to promote the use of long-acting reversible contraception (IUDs and implants) and to reduce unintended pregnancies in our region. This analysis includes those participants who received their baseline contraceptive method within 3 months of enrollment and who reached the 12-month follow-up telephone survey time point (n=4,167).

RESULTS

Sixty-eight percent of our participants chose a long-acting reversible contraception method (45% levonorgestrel intrauterine system, 10% copper IUD, and 13% subdermal implant), 23% chose combined hormonal methods (11% OCPs, 10% vaginal ring, and 2% transdermal patch), and 8% chose depot medroxyprogesterone acetate. Long-acting reversible contraception users had higher 12-month continuation rates (86%) than OCP users (55%). The two IUDs had the highest 12-month continuation rates: levonorgestrel intrauterine system (88%) and copper IUD (84%). Women using the implant also had very high rates of continuation at 1 year (83%). Satisfaction mirrored continuation: more than 80% of users were satisfied with the IUD compared with 54% satisfied with OCPs.

CONCLUSION

IUDs and the subdermal implant have the highest rates of satisfaction and 12-month continuation. Given that long-acting reversible contraception methods have the highest contraceptive efficacy, these methods should be the first-line contraceptive methods offered to patients.

Diaphragm and lubricant gel for prevention of HIV acquisition in southern African women: a randomised controlled trial

BACKGROUND

Female-controlled methods of HIV prevention are urgently needed. We assessed the effect of provision of latex diaphragm, lubricant gel, and condoms (intervention), compared with condoms alone (control) on HIV seroincidence in women in South Africa and Zimbabwe.

METHODS

We did an open-label, randomised controlled trial in HIV-negative, sexually active women recruited from clinics and community-based organisations, who were followed up quarterly for 12-24 months (median 21 months). All participants received an HIV prevention package consisting of pre-test and post-test counselling about HIV and sexually transmitted infections, testing, treatment of curable sexually transmitted infections, and intensive risk-reduction counselling. The primary outcome was incident HIV infection. This study is registered with ClinicalTrials.gov, number NCT00121459.

FINDINGS

Overall HIV incidence was 4.0% per 100 woman-years: 4.1% in the intervention group (n=2472) and 3.9% in the control group (n=2476), corresponding to a relative hazard of 1.05 (95% CI 0.84-1.32, intention-to-treat analysis). The proportion of women using condoms was significantly lower in the intervention than in the control group (54%vs 85% of visits, p<0.0001). The proportions of participants who reported adverse events (60% [1523] vs 61% [1529]) and serious adverse events (5% [130] vs 4% [101]) were similar between the two groups.

INTERPRETATION

We observed no added protective benefit against HIV infection when the diaphragm and lubricant gel were provided in addition to condoms and a comprehensive HIV prevention package. Our observation that lower condom use in women provided with diaphragms did not result in increased infection merits further research. Although the intervention seemed safe, our findings do not support addition of the diaphragm to current HIV prevention strategies.

Comparison of ethinylestradiol pharmacokinetics in three hormonal contraceptive formulations: the vaginal ring, the transdermal patch and an oral contraceptive

This open-label, randomized study compared the pharmacokinetics of ethinylestradiol (EE) from the contraceptive vaginal ring NuvaRing (15 microg EE/day), the transdermal patch (20 microg EE/day) and a combined oral contraceptive (COC) containing 30 microg EE. After 2-8 weeks of synchronization by COC treatment, subjects were randomized to 21 days of treatment with NuvaRing, patch or COC. Analysis of area under the EE concentration-versus-time curve (AUC) during 21 days of treatment showed that exposure to EE in the NuvaRing group was 3.4 times lower than in the patch group (p < .05) and 2.1 times lower than in the pill group (p < .05). Serum EE levels of subjects showed much lower variation with NuvaRing than with the patch or the COC. Thus, exposure to EE was significantly lower with NuvaRing than with the patch and pill methods, demonstrating that NuvaRing is a low-estrogen-dose contraceptive method that also results in low estrogen exposure.

Chlamydia trachomatis: its role in tubal infertility

We compared the prevalence of antibody to Chlamydia trachomatis among 88 women undergoing an evaluation for infertility and 49 women attending an antenatal clinic. Demographic data regarding sexual behavior were also collected. Eighteen women had tubal infertility and 70 had infertility due to a variety of other reasons. In comparison with women who had other causes for infertility, women with tubal infertility began coitus sooner (17.7 +/- 2.2 years vs. 19.5 +/- 3.4 years, P less than .05) and had more lifetime sex partners (4.5 vs. 1.33, P less than .001). Women with tubal infertility had a higher prevalence of antibody to C. trachomatis (13 of 18) than did women with nontubal causes for infertility (6 of 70, P less than .0001) or pregnant women (11 of 49, P = .0003). This high prevalence of antibody to C. trachomatis among women with tubal infertility was independent of sexual experience. By immunoblot analysis, an antigen of approximately 57,000 Da was immunodominant in 11 of 13 seropositive subjects with tubal infertility vs. 2 of 6 seropositive subjects with nontubal infertility (P = .046) and 1 of 11 seropositive pregnant women (P = .0003). Thus, women with tubal infertility frequently have serological evidence of prior infection with C. trachomatis and have a distinctive antigen-specific humoral immune response. These results further support the etiologic role of infection with C. trachomatis in tubal infertility.

Collagen sponge: theory and practice of medical applications

Theoretical as well as practical-clinical applications of one form of collagen (collagen sponge) as a biodegradable material is reviewed. The role of porosity of the sponge and surface characteristics of the meshwork in relation to cell ingrowth are considered essential features of collagen sponge. Rate of resorption and antigenicity could be controlled by graded crosslinking of collagenous framework. Four basic examples of clinical use of collagen sponge are presented: as wound (burn) dressing material, as a matrix, for bone and cartilage repair, as an intravaginal contraceptive diaphragm, and as surgical tampons.

Correlation of behaviors with microbiological changes in vaginal flora

Bacterial vaginosis (BV) is characterized by dramatic changes in the vaginal ecosystem. Women without evidence of vaginal infection may exhibit transient changes in their flora. We prospectively followed up women by using diaries and self-obtained vaginal smears to correlate behaviors with changes in flora. The majority of women (38/51, 78%) had significant, although transient, changes. Behaviors associated with unstable flora were a history of BV, a greater number of partners, and more frequent episodes of receptive oral sex. Only the latter remained significantly associated in the multivariate analysis. Variables that were associated with day-to-day variability in the flora included use of vaginal medication, menses, greater number of partners, spermicide use, more frequent vaginal intercourse, and less frequent use of condoms. Only a minority of women (11/51, 22%) maintained a "normal" lactobacillus-predominant flora. Factors associated with instability of the flora are similar to those epidemiologically associated with BV.

The incidence of HIV infection among women using family planning methods in Dar es Salaam, Tanzania

OBJECTIVES

To determine the risk factors for HIV seroconversion and assess the association between contraceptive use and HIV infection among women attending three large family planning clinics in Dar es Salaam, Tanzania.

DESIGN

Prospective cohort study.

METHODS

Between 1992 and 1995, 2471 HIV-negative women were followed prospectively. Information about sociodemographic characteristics, sexual behavior, contraceptive use and other risk factors was collected at recruitment and updated at follow-up visits. At the end of the study, specimens were collected for HIV testing and laboratory diagnosis of sexually transmitted diseases.

RESULTS

The overall HIV incidence was 3.4 per 100 person-years [95% confidence interval (Cl), 2.6-4.1]. The risk of HIV seroconversion decreased with increasing age (P=0.04, test for trend). Women reporting three or more sex partners during the follow-up period had the highest risk of HIV [age-adjusted relative risk (RR), 4.89; 95% Cl, 2.61-9.17]. Having an uncircumcised husband was associated with a significantly increased risk of HIV (age-adjusted RR, 3.60; 95% Cl, 1.12-11.59). The risk of HIV was also significantly increased among women with gonorrhoea (age-adjusted RR, 3.51; 95% Cl, 1.60-7.71) and candidiasis at baseline (age-adjusted RR, 1.98; 95% Cl, 1.17-3.33) and among women reporting alcohol consumption during the follow-up period. After controlling for other risk factors, the risk of HIV infection amongst users of oral contraceptive, intrauterine device and injectable contraceptive was not significantly increased. Similarly, there was no significant trend associated with increasing duration of use of any of these contraceptive methods.

CONCLUSION

These findings confirm that a large number of new HIV infections continue to occur in this population. Reassuringly, no significant association was observed between HIV and use of specific contraceptive methods. Interventions to reduce further spread of HIV are still urgently needed.

Epidemiology of endometriosis in women attending family planning clinics

OBJECTIVE

To describe the epidemiology of endometriosis in women attending family planning clinics with special reference to contraceptive methods.

DESIGN

Non-randomised cohort study with follow up of subjects for up to 23 years. Disease was measured by first hospital admission rates since endometriosis can be diagnosed with accuracy only at laparotomy or laparoscopy.

SETTING

17 family planning centres in England and Scotland.

SUBJECTS

17,032 married white women aged 25-39 years at entry during 1968-74 who were taking oral contraceptives or using an intrauterine device or diaphragm. About 99% of the women approached agreed to participate and annual loss to follow up was about 0.3%.

MAIN OUTCOME MEASURES

Diagnosis of endometriosis, age, parity, and history of contraceptive use.

RESULTS

Endometriosis was significantly related to age, peaking at ages 40-44 (chi 2 for heterogeneity = 30.9, p < 0.001). Endometriosis was not linked to duration of taking oral contraceptives. Nevertheless, the risk of endometriosis was low in women currently taking oral contraceptives (relative risk 0.4; 95% confidence interval 0.2 to 0.7), but higher in women who had formerly taken them (1.8; 1.0 to 3.1 in women who had stopped 25-48 months previously) compared with women who had never taken the pill. A similar pattern was seen for use of intrauterine devices (relative risk 0.4 (0.2 to 0.7) in current users and 1.4 (0.4 to 3.2) in users 49-72 months previously compared with never users). No association was found between endometriosis and use of the diaphragm.

CONCLUSIONS

Oral contraceptives seem to temporarily suppress endometriosis. Endometriosis may be diagnosed late in women using intrauterine devices as pain and bleeding occur with both.

The combined contraceptive vaginal ring, NuvaRing: an international study of user acceptability

The acceptability of the combined contraceptive vaginal ring, NuvaRing, was assessed during two trials conducted in North America and Europe. Women completed a questionnaire about the ring's clarity of instructions, ease of use, sexual comfort, cycle-related characteristics and satisfaction after 3, 6 and 13 cycles of use. A total of 1,950 women (82% of those recruited) completed a questionnaire at cycle 3. At baseline, 66% of participants preferred oral contraceptives, but after three cycles of ring use 81% preferred the ring. On study completion, 97% agreed that the instructions for use were clear; 85% of women and 71% of their partners never/rarely felt the ring during intercourse and 94% of partners never/rarely minded that the woman was using the ring. Overall acceptance was high, 96% were satisfied with the ring and 97% would recommend the ring. Similar responses were seen for women who prematurely discontinued from the studies, except that slightly fewer women were satisfied (60%) and would recommend the ring (75%). Reasons for liking the ring included 'not having to remember anything' (45%) and 'ease of use' (27%). In conclusion, there is a high level of user and partner acceptability for the contraceptive ring.

Efficacy, cycle control, and user acceptability of a novel combined contraceptive vaginal ring

OBJECTIVE

To assess the contraceptive efficacy, cycle control, tolerability, and user acceptability of a novel combined contraceptive vaginal ring for up to 13 cycles.

METHODS

Healthy women requesting contraception were enrolled in this 1-year multicenter study. Each ring released 120 microg of etonogestrel and 15 microg of ethinylestradiol daily, and was used for 3 weeks followed by a 1-week ring-free period.

RESULTS

A total of 2322 women started treatment and so formed the intent-to-treat population. Subjects were followed for 23,298 cycles, equivalent to 1786 woman-years. Compliance was good with 85.6% of cycles in full compliance with specified criteria. In the intent-to-treat population, 21 pregnancies occurred, giving a Pearl Index of 1.18 (95% confidence interval 0.73, 1.80). Eleven of the pregnancies were attributable to noncompliance; the Pearl Index for the per-protocol population was 0.77 (95% confidence interval 0.37, 1.40). The mean incidence of withdrawal bleeding was 98.5% in all cycles. Irregular bleeding occurred in 5.5% of all cycles, and in most women, early or late withdrawal bleeding was restricted to spotting. The ring was well tolerated with a low incidence of adverse events; only 2.5% of all discontinuations were device related. The ring was easy to insert and remove and did not interfere with intercourse. Eighty-five percent of women were satisfied with the ring, and 90% would recommend its use to others.

CONCLUSION

The ring is an effective contraceptive with excellent cycle control that is convenient, well tolerated, and highly acceptable to users.

Mortality among women participating in the Oxford/Family Planning Association contraceptive study

43 deaths are known to have occurred among the 17 032 participants in the Oxford/Family Planning Association contraceptive study up to the end of April, 1977. 9 deaths from cardiovascular causes have been observed among the women in the oral-contraceptive entry group (49 681 woman-years of observation) while no such deaths have been observed among the women who entered the study while using a diaphragm or an intrauterine device (39 146 woman-years of observation). These findings are consistent with the results presented in the accompanying report from the Royal College of General Practitioners Oral Contraception Study.

Incorporation of C14-amino acids into protein of isolated diaphragms: an effect of insulin independent of glucose entry

The effect of glucose concentration and insulin on protein synthesis was investigated using the isolated rat diaphragm and C14-labeled amino acids. When the donor rat has been well fed, the incorporation of histidine-2-C14, lysine-2-C14, phenylalanine-3-C14, and alanine-1-C14 into muscle protein is uninfluenced by glucose concentration in the medium over the range 0–600 mg %. Insulin leads to an increase in C14-amino acid incorporation into muscle protein in the absence of glucose in the medium. This positive effect of insulin in the absence of added glucose is still observed when the diaphragms are pre-incubated for 2 hours prior to adding insulin. These findings suggest an effect of insulin on protein metabolism independent of its action in promoting glucose entry.

Intravaginal ring delivery of the reverse transcriptase inhibitor TMC 120 as an HIV microbicide

TMC 120 (Dapivirine) is a potent non-nucleoside reverse transcriptase inhibitor that is presently being developed as a vaginal HIV microbicide. To date, most vaginal microbicides under clinical investigation have been formulated as single-dose semi-solid gels, designed for application to the vagina before each act of intercourse. However, a clear rationale exists for providing long-term, controlled release of vaginal microbicides in order to afford continuous protection against heterosexually transmitted HIV infection and to improve user compliance. In this study we report on the incorporation of various pharmaceutical excipients into TMC 120 silicone, reservoir-type intravaginal rings (IVRs) in order to modify the controlled release characteristics of the microbicide. The results demonstrate that TMC 120 is released in zero-order fashion from the rings over a 28-day period and that release parameters could be modified by the inclusion of release-modifying excipients in the IVR. The hydrophobic liquid excipient isopropyl myristate had little effect on steady-state daily release rates, but did increase the magnitude and duration of burst release in proportion to excipient loading in the IVR. By comparison, the hydrophobic liquid poly(dimethylsiloxane) had little effect on TMC 120 release parameters. A hydrophilic excipient, lactose, had the surprising effect of decreasing TMC 120 burst release while increasing the apparent steady-state daily release in a concentration-dependent manner. Based on previous cell culture data and vaginal physiology, TMC120 is released from the various ring formulations in amounts potentially capable of maintaining a protective vaginal concentration. It is further predicted that the observed release rates may be maintained for at least a period of 1 year from a single ring device. TMC 120 release profiles and the mechanical properties of rings could be modified by the physicochemical nature of hydrophobic and hydrophilic excipients incorporated into the IVRs.

Use of the novel combined contraceptive vaginal ring NuvaRing for ovulation inhibition

OBJECTIVE

To assess the effects of the combined contraceptive vaginal ring NuvaRing on ovarian function.

DESIGN

Randomized, open-label, crossover study.

SETTING

Clinical pharmacology unit.

PARTICIPANT(S)

Sixteen healthy female volunteers.

INTERVENTION(S)

Group 1: one cycle of combined oral contraceptive containing desogestrel (150 microg) and ethinyl estradiol (30 microg) (desogestrel/EE COC), followed by a NuvaRing treatment period. Group 2: NuvaRing treatment period followed by a cycle of desogestrel/EE COC.

MAIN OUTCOME MEASURE(S)

Follicular diameter, serum hormone concentrations (follicle-stimulating hormone, 17beta estradiol, luteinizing hormone, and progesterone), and endometrial thickness.

RESULT(S)

NuvaRing use for the recommended period of 3 weeks resulted in complete inhibition of ovulation, as assessed by vaginal ultrasound (follicular diameter) and by serum luteinizing hormone and progesterone concentrations. Inhibition of ovulation was maintained for an additional 2 weeks of NuvaRing use. Ovarian suppression between the groups was comparable. Furthermore, ovarian suppression after 3 weeks of NuvaRing use was comparable to that on day 21 of DGS/EE COC intake. NuvaRing was well tolerated.

CONCLUSION(S)

NuvaRing completely inhibited ovulation throughout the normal 3-week period and the extended period of use. Ovarian suppression was comparable to that with desogestrel/EE COC.

Long-term, controlled release of the HIV microbicide TMC120 from silicone elastomer vaginal rings

OBJECTIVES

The feasibility of providing prolonged and controlled release of the experimental non-nucleoside reverse transcriptase inhibitor TMC120 from a silicone vaginal ring in quantities sufficient to maintain a vaginal concentration offering protection against heterosexual HIV transmission was investigated.

METHODS

Core-type, silicone elastomer vaginal rings containing TMC120 were manufactured, and in vitro release studies performed under sink conditions. The experimental release data, as determined by HPLC, were correlated with estimates of vaginal TMC120 concentrations required to inhibit HIV replication.

RESULTS

Continuous, zero-order release of TMC120 from core-type vaginal rings was observed in vitro over a 71 day period, equivalent to 136 microg/day. The release rate is predicted to maintain vaginal concentrations of the antiretroviral in the range of several orders of magnitude in excess of reported HIV inhibitory concentration values.

CONCLUSIONS

Continuous and prolonged zero-order release of TMC120 from a silicone vaginal ring device at quantities predicted to prevent HIV infection was observed.

In vitro release properties of etonogestrel and ethinyl estradiol from a contraceptive vaginal ring

The release properties of steroids from a combined contraceptive vaginal ring have been investigated. The product design is based on a coaxial fiber consisting of two types of polyethylene vinylacetate copolymers. Inside the core of the fiber, two steroids are present in a molecularly dissolved state. In order to design a controlled release system with specified release characteristics, values of diffusion coefficient and solubility are required. These data can either be determined during pre-formulation studies on e.g. polymeric flat films or from in-vitro release measurements of the actual coaxial fibers. It can be concluded from this study that polyethylene vinylacetate copolymers exhibit suitable properties to develop a controlled release system with the two steroids etonogestrel and ethinyl estradiol. It has been found that the permeability data obtained in the pre-formulation studies are useful in semi-quantitative terms, but deviate from the permeability data found from the in-vitro release of coaxial fibers. This is most likely due to differences in the polymeric structure of films and coaxial fibers. As a consequence, further studies should be initiated to evaluate the relationship between the manufacturing process and the resulting polymeric structure. It has also been found that the solubility and release of etonogestrel are influenced by the concentration of ethinyl estradiol. By investigating this phenomenon by thermoanalysis, it was shown that the steroids form an eutectic. The lower melting point of the steroids results in an increase in solubility and hence in altered permeability properties.

Barrier contraceptives and sexually transmitted diseases in women: a comparison of female-dependent methods and condoms

INTRODUCTION

Most efforts at sexually transmitted disease (STD) protection center on condom use, but little is known about how condoms compare with other barrier methods, particularly those controlled by women.

METHODS

To evaluate the effect of different barrier contraceptives on the prevalence of STDs and other vaginal infections, we retrospectively studied 5681 visits by women to an urban STD clinic.

RESULTS

As compared with women using no contraceptive or with tubal ligations, women using the contraceptive sponge or diaphragm had at least 65% lower rates of infection with Neisseria gonorrhoeae and Trichomonas vaginalis, while condom users had 34% and 30% lower rates, respectively. For Chlamydia trachomatis, the reduction was 13% among sponge users, 72% among diaphragm users, and 3% among condom users, although these differences were not significant. When compared with women using condoms, women using female-dependent methods (sponge or diaphragm) had significantly lower rates of both gonorrhea and trichomoniasis. Vaginal candidiasis was more common among women using diaphragms but not other barrier methods, while rates of bacterial vaginosis were similar among all groups.

CONCLUSIONS

Women using the contraceptive sponge or diaphragm experience protection from STDs to a greater extent than those relying on condoms. Female-dependent barrier contraceptives should receive more attention in STD risk-reduction programs.

Commentary: methods women can use that may prevent sexually transmitted disease, including HIV

Although sexually transmitted diseases, including human immunodeficiency virus (HIV), are a major concern for women, few prevention messages are targeted specifically to women. Those that are generally stress abstaining, altering the number or selection of partners, and urging partners to use condoms. But these behaviors may be unrealistic for many women, particularly women who are at highest risk for sexually transmitted diseases, because they require significant changes in life-style or depend on male-controlled condom use. Recommendation of contraceptives for prevention of sexually transmitted diseases depends largely on how well specific methods perform under controlled conditions, either in the laboratory or in clinical trials. Observational studies, which better reflect day-to-day use, indicate that condoms, barriers, and spermicides, used properly and consistently, can provide substantial protection against various sexually transmitted diseases. Condoms can similarly help protect against HIV, but studies of barriers and spermicides are scant and currently inconclusive. Finally, those methods that are controlled by women are consistently more effective in preventing sexually transmitted diseases. Thus, although condoms used well are still the best choice, the imperative for female-controlled methods indicates that diaphragms and spermicides should receive greater emphasis in prevention messages.

Eliminating health disparities in unintended pregnancy with long-acting reversible contraception (LARC)

Significant public health disparities exist surrounding teen and unplanned pregnancy in the United States. Women of color and those with lower education and socioeconomic status are at much greater risk of unplanned pregnancy and the resulting adverse outcomes. Unplanned pregnancies reduce educational and career opportunities and may contribute to socioeconomic deprivation and widening income disparities. Long-acting reversible contraception (LARC), including intrauterine devices and implants, offer the opportunity to change the default from drifting into parenthood to planned conception. LARC methods are forgettable; once placed, they offer highly effective, long-term pregnancy prevention. Increasing evidence in the medical literature demonstrates the population benefits of use of these methods. However, barriers to more widespread use of LARC methods persist and include educational, access, and cost barriers. With increasing insurance coverage under the Affordable Care Act and more widespread, no-cost coverage of methods, more and more women are choosing intrauterine devices and the contraceptive implant. Increasing the use of highly effective contraceptive methods may provide one solution to the persistent problem of the health disparities of unplanned and teen pregnancies in the United States and improve women's and children's health.

Effects on cycle control and bodyweight of the combined contraceptive ring, NuvaRing, versus an oral contraceptive containing 30 g ethinyl estradiol and 3 mg drospirenone

BACKGROUND

The objective of this study was to compare cycle control, cycle-related characteristics and bodyweight effects of NuvaRing with those of a combined oral contraceptive (COC) containing 30 microg of ethinyl estradiol and 3 mg of drospirenone.

METHODS

A randomized, multicentre, open-label trial in which 983 women were treated (intent-to-treat population) with NuvaRing or the COC for 13 cycles.

RESULTS

Breakthrough bleeding or spotting during cycles 2-13 was in general less frequent with NuvaRing than that with the COC (4.7-10.4%) and showed a statistically significant odds ratio of 0.61 (95% confidence interval: 0.46, 0.80) with longitudinal analysis. Intended bleeding was significantly better for all cycles with NuvaRing (55.2-68.5%) than that with the COC (35.6-56.6%) (P < 0.01). Changes from baseline in mean bodyweight and body composition parameters were relatively small for both groups with no notable between-group differences.

CONCLUSION

NuvaRing was associated with better cycle control than the COC, and there was no clinically relevant difference between the two groups in bodyweight.

Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and unwanted pregnancy

The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and unwanted pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.