Time to pregnancy recognition among users of an FDA-cleared fertility application.

Background: Previous investigations of time-to-pregnancy recognition have analysed data from national surveys and clinics, but this has not been investigated in the context of digital fertility applications. Timely pregnancy recognition can help individuals in health and pregnancy management, reducing maternal and foetal risk and costs, whilst increasing treatment options, availability, and cost. Methods: This dataset contained 23,728 pregnancies (conceived between June 2018 and December 2022) from 20,429 participants using a Food and Drug Administration (FDA) cleared fertility app in the United States. Most participants (with non-missing information) identified as Non-Hispanic White, and one-third reported obtaining a university degree. We used two-tailed Welch's t-test, Mann-Whitney U-test, and two-tailed Z-tests to compare time to pregnancy recognition between those using the app to conceive or contracept. Results: Participants using an app to conceive recognised pregnancy on average at 31.3 days from last menstrual period (LMP) compared to 35.9 days among those using the app to prevent pregnancy. Conclusion: Generalisability is limited, as all participants were using a fertility app and had relatively homogenous sociodemographic characteristics.

People who recognise pregnancy early may benefit, as earlier recognition can reduce costs and risks, and make more treatment options available. In the past, researchers have studied the time it takes for an individual to recognise that they are pregnant by asking them in national surveys or when they attend a clinic. However, with the advent of digital fertility tracking apps, we investigated the time it takes to recognise pregnancy when using such an app. We analysed data from 23,728 pregnancies from 20,429 users of the Natural Cycles app between June 2018 and December 2022. We found that participants using the app to try to get pregnant recognised pregnancy an average of 4.6 days earlier than those using the app to prevent pregnancy.

Drospirenone and estetrol: evaluation of a newly approved novel oral contraceptive.

INTRODUCTION: Estetrol (E4) is a native estrogen produced only by the fetal liver during pregnancy. E4 is the first new estrogen to be used in hormonal contraception since the introduction of oral contraceptives in 1960. Ethinyl estradiol, the most commonly used estrogen in oral contraceptives today, increases the risks of thromboembolism and has other significant hepatic impacts, which induce important drug-drug interactions. On the other hand, Phase 2 E4 characterization studies demonstrated that E4 has negligible impacts on liver, breast, and vascular endothelium due to its distinct tissue selectivity. Combined with drospirenone (DRSP), E4 offers an improved safety profile for oral contraception. AREAS COVERED: This paper briefly highlights the unique pharmacokinetic and pharmacodynamic features of E4. The efficacy, safety, and tolerability results from the Phase 2 and 3 studies of the E4/DRSP pill are discussed to provide the reader with a thorough understanding of E4 and information to use when counseling potential users. EXPERT OPINION: The estetrol/drospirenone oral contraceptive is effective and well tolerated and provides good cycle control. In the future, estetrol may be the estrogen of choice if subsequent evidence verifies that it reduces the risks associated with current estrogens, such as venous thromboembolism and drug-drug interactions.

Satisfaction with a Segesterone Acetate and Ethinyl Estradiol Contraceptive Vaginal System Among Recent Oral Contraceptive or Hormonal Contraceptive Vaginal Ring Users.

Background: We evaluated satisfaction with use of a segesterone acetate and ethinyl estradiol (0.15/0.013 mg) contraceptive vaginal system (CVS) among women who had recently used a monthly contraceptive vaginal ring or contraceptive pills. The CVS is a ring-shaped device used in a 21-days-in/7-days-out regimen for 13 cycles. Materials and Methods: We analyzed post hoc satisfaction responses at cycle 3 and end of study (EOS) from a subset of participants with documented recent use of the monthly ring or daily pills before enrollment in a multinational, phase 3, 13-cycle trial evaluating the CVS. EOS included results from participants who had completed ≥10 cycles. Results were summarized descriptively. Results: We identified 128 recent ring and 219 recent pill users at cycle 3 (of 1033 survey participants), and 92 and 148, respectively, at EOS (of 622 survey participants); overall satisfaction with CVS use was high (≥90%). At EOS, most ring (89%) and pill (97%) users liked the CVS as much/better than any previous method. The two most-liked CVS features included ease of use and 1-year duration; the two most disliked features included ring insertion and feeling it coming out. At EOS, ≥88% of both groups reported no concern about using the same CVS for a year, and most (>80%) had recommended it to friends or family members. Conclusion: The CVS clinical trial participants who were recent ring/pill users reported high satisfaction and liked it as much/better than any previously used contraceptive; the CVS may be a good contraceptive option for switchers. Clinical trial registration NCT00263341.

Unmet Needs Discussed on Reddit by Women with Premenstrual Dysphoric Disorder.

Premenstrual dysphoric disorder (PMDD) is a disabling disorder that impacts 1.8 percent to 5.8 percent of menstruating women for 1-2 weeks each month. Many affected women turn to social media platforms for the information and the support they feel that they do not get from other sources. We sought to better understand the most strongly expressed unmet needs of women with PMDD by analyzing their posts and comments on one of the largest social media platforms (Reddit), which has been providing important insights into other medical problems. We searched Reddit using the subreddit title "r/PMDD" for posts from January 2020 through November 2021. To identify the most prevalent issues, we included all written posts with a submission score of at least 5 and at least three comments. Two authors classified each post; inconsistencies were resolved by a third reviewer. Over 800 posts were reviewed; 250 met study criteria; additionally, over 875 comments were evaluated. Four main themes emerged from the analysis: emotional responses to PMDD; unanswered questions women had about the diagnosis and treatment of PMDD; the impact that PMDD had on personal relationships, and, finally, the recommendations women made to others based on their own experience, accurate or not. These themes are detailed in this article to provide insights into what many women with PMDD experience and what their frustrations and misunderstandings are about the condition so that clinicians may better help address women's unspoken questions and correct their possible misinformation.

Continuation rates of two different-sized copper intrauterine devices among nulliparous women: Interim 12-month results of a single-blind, randomised, multicentre trial.

Background: The most widely used copper intrauterine device (IUD) in the world (the TCu380A), and the only product available in many countries, causes side effects and early removals for many users. These problems are exacerbated in nulliparous women, who have smaller uterine cavities compared to parous women. We compared first-year continuation rates and reasons/probabilities for early removal of the TCu380A versus a smaller Belgian copper IUD among nulliparous users. Methods: This 12-month interim report is derived from a pre-planned interim analysis of a sub population and focused on key secondary comparative endpoints. In this participant-blinded trial at 16 centres in the USA, we randomised participants aged 17-40 in a 4:1 ratio to the NT380-Mini or the TCu380A. In the first year, participants had follow-up visits at 6-weeks and 3, 6, and 12-months, and a phone contact at 9 months; we documented continued use, expulsions, and reasons for removal. Among participants with successful IUD placement, we compared probabilities of IUD continuation and specific reasons for discontinuation using log-rank tests. This trial is registered with ClinicalTrials.gov number NCT03124160 and is closed to recruitment. Findings: Between June 1, 2017, and February 25, 2019, we assigned 927 nulliparous women to either the NT380-Mini (n = 744) or the TCu380A (n = 183); the analysis population was 732 (NT380-Mini) and 176 (TCu380A). Participants using the NT380-Mini, compared to the TCu380A, had higher 12-month continuation rates (78·7% [95% CI: 72·9-84·5%] vs. 70·2% [95% CI: 59·7-80·7], p = 0·014), lower rates of removal for bleeding and/or pain (8·1% vs. 16·2%, p = 0·003) and lower IUD expulsion rates (4·8% vs. 8·9%, p = 0·023), respectively. Interpretation: The NT380-Mini offers important benefits for a nulliparous population compared to the TCu380A in the first twelve months, when pivotal experiences typically occur. Higher continuation rates with the NT380-Mini may avert disruptions in contraceptive use and help users avoid unintended pregnancy. Funding: Bill & Melinda Gates Foundation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and Mona Lisa, N.V. (Belgium).

Evaluation of ovulation and safety outcomes in a multi-center randomized trial of three 84 day ulipristal acetate regimens.

OBJECTIVES: To describe ovulation inhibition and safety of daily oral ulipristal acetate (UPA) over 84 days. STUDY DESIGN: This multi-center phase 1 and/or 2 trial randomized participants to use oral ulipristal 10 mg or 5 mg daily or a 3 cycle regimen of 5 mg for 24 days followed by four placebo days. We stratified randomization by body mass index (BMI) <32 or 32-40 kg/m2. To estimate ovulation inhibition, the primary outcome, participants underwent transvaginal ultrasound and blood sampling twice weekly; we analyzed compliant participants who completed the 84 day study. Safety endpoints included 3 endometrial biopsies and liver chemistry tests. RESULTS: We enrolled 180 participants and included 137 in the ovulation inhibition analyses. Progesterone values that remained below 3ng/mL throughout treatment suggested consistent ovulation inhibition in 52 of 137 (38%) participants; 25 of 47(53%), 20 of 44(45%), and 7 of 46(15%) among participants randomized to the 10 mg, 5 mg, and cyclic treatments, respectively (p < 0.01). Progesterone values consistently <3 ng/mL were more frequent in participants with a BMI > 32kg/m2 (25/50(50%) vs 27/87(31%), p = 0.01). Average ulipristal concentrations were higher among participants with low progesterone concentrations (p < 0.01). Endometrial biopsies during treatment showed progesterone-receptor-modulator-associated endometrial changes in 52 of 164 participants (32%); 22 of 49(40%), 16 of 48(29%), and 14 of 51(26%) in women randomized to the 10 mg, 5 mg, and the cyclic treatments, respectively (p = 0.07, test-for-trend); these changes resolved after treatment cessation. Liver transaminase changes were rare. CONCLUSIONS: Oral ulipristal acetate over 12 weeks did not reliably suppress ovulation, particularly in the 5 mg cyclic-dose group. Ovulation inhibition and endometrial changes were dose dependent. Reversible endometrial changes occurred during treatment. IMPLICATIONS: Progesterone-receptor modulators have been suggested for daily oral contraception. Since progesterone concentrations suggest that ovulation occurred during treatment, further studies would be necessary to assess whether these were functional ovulations and to evaluate other possible mechanisms of contraception.

Detecting variations in ovulation and menstruation during the COVID-19 pandemic, using real-world mobile app data.

BACKGROUND: As war and famine are population level stressors that have been historically linked to menstrual cycle abnormalities, we hypothesized that the COVID-19 pandemic could similarly affect ovulation and menstruation among women. METHODOLOGY: We conducted a retrospective cohort study examining changes in ovulation and menstruation among women using the Natural Cycles mobile tracking app. We compared de-identified cycle data from March-September 2019 (pre-pandemic) versus March-September 2020 (during pandemic) to determine differences in the proportion of users experiencing anovulation, abnormal cycle length, and prolonged menses, as well as population level changes in these parameters, while controlling for user-reported stress during the pandemic. FINDINGS: We analyzed data from 214,426 cycles from 18,076 app users, primarily from Great Britain (29.3%) and the United States (22.6%). The average user was 33 years of age; most held at least a university degree (79.9%). Nearly half (45.4%) reported more pandemic-related stress. Changes in average cycle and menstruation lengths were not clinically significant, remaining at 29 and 4 days, respectively. Approximately 7.7% and 19.5% of users recorded more anovulatory cycles and abnormal cycle lengths during the pandemic, respectively. Contrary to expectation, 9.6% and 19.6% recorded fewer anovulatory cycles and abnormal cycle lengths, respectively. Women self-reporting more (32.0%) and markedly more (13.6%) stress during the pandemic were not more likely to experience cycle abnormalities. CONCLUSIONS: The COVD-19 pandemic did not induce population-level changes to ovulation and menstruation among women using a mobile app to track menstrual cycles and predict ovulation. While some women experienced abnormalities during the pandemic, this proportion was smaller than that observed prior to the pandemic. As most app users in this study were well-educated women over the age of 30 years, and from high-income countries, their experience of the COVID-19 pandemic might differ in ways that limit the generalizability of these findings.

The new low-dose transdermal contraceptive system (Twirla®): results from preclinical and Phase III trials.

A new low-dose, once-a-week contraceptive transdermal delivery system (TDS) with 2.3-mg ethinyl estradiol (EE) and 2.6-mg levonorgestrel (LNG; Twirla®) has recently been approved by the US FDA for contraception of women with BMI <30 kg/m2. The rationale for developing this new patch, the preclinical study results and the results from two innovative Phase III clinical trials demonstrate that this patch has an acceptable Pearl index (4.3%) for its indicated users and has safety and tolerability comparable to other similar dose oral combined hormonal contraceptives. This new TDS provides an improvement over the existing TDS products, with significantly lower steady-state estrogen exposure, a level equal to that with 30-µg EE containing oral contraceptives.

Lay abstract A new patch with lower doses of estrogen than existing contraceptive patches has been approved by the US FDA for birth control for women who are not obese. It has been tested in two large clinical trials that included women who are like the general population of reproductive age women in the USA. Up-to-date electronic diaries were used to get the most accurate information to use to counsel women who might appreciate the convenience of once-a-week patch use. The patch worked better in lighter women than those who were heavier, and it appears to be safer in women with lower BMIs too.

Efficacy, safety, and tolerability of a levonorgestrel/ethinyl estradiol transdermal delivery system: Phase 3 clinical trial results.

OBJECTIVE: To assess the contraceptive efficacy, safety, and tolerability of a contraceptive transdermal delivery system, (TDS; TWIRLAⓇ) containing levonorgestrel (LNG) and ethinyl estradiol (EE). STUDY DESIGN: This single-arm, open-label, multicenter, 1-year (13 cycle), phase 3 study enrolled sexually active women ≥18 years old at risk for pregnancy irrespective of body mass index (BMI). Women used patches in 28-day cycles (3 consecutive administrations of 7-day patches followed by 7 days off-treatment/patch-free week). We assessed contraceptive efficacy by the Pearl Index (PI) in women 18 to 35 years, excluding cycles without intercourse or when other contraceptive methods were used. RESULTS: The study enrolled 2032 demographically diverse women in the US, of which 35.3% had a BMI ≥30 kg/m2. In the primary efficacy analysis, the PI (95% confidence interval) was 5.8 (4.5-7.2) pregnancies per 100 woman-years. PIs trended higher as BMI increased; the PI was 4.3 (2.9-5.8) in women with BMI <30 kg/m2 and 8.6 (5.8-11.5) in women with BMI ≥30 kg/m2. Hormone-related treatment-emergent adverse events included nausea (4.1%) and headache (3.6%); 11% of women discontinued due to adverse events. Four women (all with BMIs ≥30 kg/m2) reported thromboembolic events considered related to treatment. CONCLUSIONS: The low-dose LNG/EE TDS was effective in preventing pregnancy in a population of women representative of US demographics. Efficacy was reduced in women with BMI ≥30 kg/m2. The TDS safety and tolerability profile was consistent with other similar dose combined hormonal contraceptives. Results of this phase 3 study supported the US Food and Drug Administration approval of TWIRLAⓇ for prevention of pregnancy in women with BMI <30 kg/m2. IMPLICATIONS: TDS (120 µg/day levonorgestrel and 30 µg/day ethinyl estradiol) is an effective, low-dose transdermal contraceptive patch with favorable tolerability profile approved for prevention of pregnancy in women with BMI <30 kg/m2. TDS has reduced effectiveness in women with BMI ≥30 kg/m2.

The potential for intramuscular depot medroxyprogesterone acetate as a self-bridging emergency contraceptive.

OBJECTIVE: To examine the rate of ovulatory disruption when intramuscular depot medroxyprogesterone acetate (DMPA) is administered across graded stages of dominant follicle development. STUDY DESIGN: We assigned enrolled participants to one of three preassigned dominant follicle size groups: 12-14 mm, 15-17 mm and ≥ 18 mm. We followed dominant follicles via serial transvaginal ultrasound (TVUS) until the follicles reached their assigned size, at which time we administered DMPA. For 5 consecutive days thereafter, we followed the follicles via TVUS to observe follicle rupture and obtained serum luteinizing hormone (LH), estradiol, and progesterone concentrations. In the following 2 weeks, we collected serum progesterone concentrations twice weekly to detect possible ovulatory delay or dysfunction. We also collected serum medroxyprogesterone acetate (MPA) concentrations at 1 and 24 h after DMPA administration to examine against ovulatory outcomes. RESULTS: Twenty-six of 29 enrolled women completed the study. DMPA suppressed ovulation in 17/26 (65%) and caused ovulatory dysfunction in 1/26 (4%) participants. Larger follicles were more likely to rupture despite DMPA (12-14 mm: 0/10 (0%); 15-17 mm: 3/10 (30%); ≥ 18 mm: 6/6 (100%); p < .01). Pre-DMPA LH concentrations ranged from 13.8 to 93.7 IU/L (mean 49.0 IU/L) in cases of follicle rupture. We observed no cases of follicle rupture when DMPA was administered through cycle day 12. All 24-h MPA concentrations exceeded those needed for ovulation suppression. CONCLUSION: DMPA suppressed and additionally disrupted ovulation in 65% and 4% of observed cycles, respectively. DMPA may provide effective emergency contraception as well as ongoing contraception if administered prior to an expected ovulation and specifically before the LH surge. IMPLICATIONS: DMPA may be an alternative form of emergency contraception that can also self-bridge to ongoing contraception. As ovulation was not observed among any follicles when DMPA was given through cycle day 12, women who initiate DMPA up through cycle day 12 may not require backup contraception.

Efficacy, Safety, and Tolerability of a New Low-Dose Copper and Nitinol Intrauterine Device: Phase 2 Data to 36 Months.

OBJECTIVE: To assess in parous and nulliparous women, the efficacy, safety, and tolerability of a new, low-dose copper (175 mm) intrauterine contraceptive with a flexible nitinol frame provided in a preloaded applicator. METHODS: Institutional review boards at 12 U.S. sites approved this commercially funded project. Patients met standard inclusion and exclusion criteria for a copper-based intrauterine device (IUD), generally consistent with the Centers for Disease Control and Prevention's U.S. Medical Eligibility Criteria for Contraceptive Use, 2016. Intrauterine device placement occurred at any day in the eligible patient's menstrual cycle after assuring she was not pregnant. The primary outcome measure assessed efficacy (measured by the Pearl Index) in this 1-year study with a 2-year extension. Secondary outcomes included placement success, ease of placement, safety as measured by adverse events, and tolerability assessed by discontinuation rate and bleeding and spotting patterns. RESULTS: A total of 286 women provided 5,640 cycles evaluable for pregnancy. Patients averaged 27.1 years of age. Nulliparous women represented 60.8% of the patients. Over 36 months of observation, we identified two pregnancies (Pearl Index 0.46 [95% CI 0.06-1.67]) and 10 serious adverse events; none were study-related. Successful placement occurred in 283 participants (99.0%). Median (range) continuation times were 2.7 years (0-3.4). We identified five expulsions (1.8%), zero uterine perforations, and one report of pelvic inflammatory disease. Adverse events prompted 30 women (10.6%) to discontinue early in the first year of use with 23 (8.1%) discontinuing for issues of bleeding, pain, or both. Altogether, 107 (37.8%) completed 36 months of device use. Mean bleeding days per cycle decreased from 7.6 in cycle 1 to 5.2 in cycle 13. CONCLUSION: The novel, low-dose copper and nitinol IUD demonstrated high efficacy and safety in this phase 2 U.S. Food and Drug Administration trial and warrants further expanded study in a phase 3 clinical trial. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02446821. FUNDING SOURCE: Sebela Pharmaceuticals, Inc.

Awareness of Pregnancy-Associated Health Risks Among Pregnant Women and Male Partners Surveyed in a Prenatal Clinic.

Background: Underestimation of pregnancy-associated health risks could compromise informed decision-making and reduce demand for preconception care. We assessed the knowledge of pregnant women and male partners about several health risks posed by pregnancy to identify potential gaps in reproductive health literacy. Materials and Methods: Pregnant women and male partners were surveyed about their knowledge of seven common health risks associated with pregnancy (venous thromboembolism [VTE], diabetes, gallstones, hemorrhoids, hypertension [HTN], kidney infection, and anemia) in either English or Spanish in a prenatal clinic at Harbor-UCLA Medical Center in Torrance, California. Results: The response rate for women was estimated to be 66% and was 85% for men. Of the 285 respondents, 5.0% of women and 5.6% of men were able to correctly report that all seven health risks increased during pregnancy. Overall, 30.6% of women and 24% of men recognized that pregnancy increased the risks of the three most serious conditions (VTE, diabetes, and HTN). While higher education was associated with a higher awareness of these three serious risks, the majority of individuals with the highest education nonetheless incorrectly reported that these risks were reduced or unchanged in pregnancy. Age, parity, language, gender, and gestational age did not impact study findings. Overall, 77.9% of respondents rated oral birth control pills more hazardous to a woman's health than pregnancy. Conclusions: Surveyed pregnant women and male partners have significant knowledge deficiencies concerning common and serious health hazards associated with pregnancy that may hamper women's ability to make informed choices about their reproductive health options.

Comprehensive overview of the recently FDA-approved contraceptive vaginal ring releasing segesterone acetate and ethinylestradiol: A new year-long, patient controlled, reversible birth control method.

Introduction: This is an overview of the recently FDA-approved silicone elastomer combined hormonal contraceptive vaginal ring (CVR), which is used cyclically for up to 1 year, eliminating resupply challenges. This ring requires no refrigeration, simplifying the supply chain. Developed by the Population Council, this CVR will soon be marketed in the United States as Annovera™ by TherapeuticsMD. Areas Covered: The composition of the elastomer ring and the chemical, pharmacokinetic and pharmacodynamic properties of both hormonal components are discussed. Results of the clinical trials of its efficacy, tolerability, safety, and acceptability follow. Finally, subanalyses from the clinical trials are presented to guide clinicians in counseling potential users. Expert Opinion: This CVR introduces a new progestin - segesterone acetate (SA) - that has no androgenic or estrogenic action in vitro or in vivo, but has the highest anti-ovulatory potential of all available progestins. SA is paired with EE in an intravaginal elastomer ring, that is used cyclically (21 days in place/7 days removed) to provide 12 months (13 cycles) of contraception. This once-a-month, self-applied CVR offers a convenient, rapidly reversible, year-long contraception with efficacy and side effect profiles similar to other combined hormonal methods, for women with BMI < 29 kg/m2.

Comparison of self-reported female condom failure and biomarker-confirmed semen exposure.

OBJECTIVE: To investigate whether rates of self-reported Woman's Condom (WC) clinical failure and semen exposure from a functionality study are comparable to results from a contraceptive efficacy substudy. STUDY DESIGN: We structured our comparative analysis to assess whether functionality studies might credibly supplant contraceptive efficacy studies when evaluating new female condom products. Couples not at risk of pregnancy in the functionality (breakage/slippage/invagination/penile misdirection) study and women in the contraceptive efficacy study completed condom self-reports and collected precoital and postcoital vaginal samples for up to four uses of the WC. Both studies used nearly identical self-report questions and the same self-sampling procedures and laboratory for prostatic specific antigen (PSA), a well-studied semen biomarker. We compared condom failure and semen exposure proportions using generalized estimating equations methods accounting for within-couple correlation. RESULTS: Ninety-five (95) efficacy substudy participants used 334 WC and 408 functionality participants used 1572 WC. Based on self-report, 19.2% WC (64 condoms) clinically failed in the efficacy substudy compared to 12.3% WC (194 condoms) in the functionality study (p=.03). Of the 207 WC efficacy uses with evaluable postcoital PSA levels, 14.5% (30 uses) resulted in semen exposure compared to 14.2% (184 uses) of the 1293 evaluable WC functionality study uses. CONCLUSIONS: When evaluating the ability of an experimental condom to prevent semen exposure, the rate of clinical condom failure reported by participants risking pregnancy in an efficacy substudy was significantly higher than the rate reported by participants not risking pregnancy in a functionality study. The rate of semen exposure, assessed by an objective biomarker was nearly identical for the two studies. IMPLICATIONS: Our results suggest that an objective marker of semen exposure in functionality studies could provide a reasonable alternative to contraceptive efficacy studies in evaluating risk of unintended pregnancy and inferring protection from sexually transmitted infection than condom failure rates based on self-report.

Efficacy of the 1-year (13-cycle) segesterone acetate and ethinylestradiol contraceptive vaginal system: results of two multicentre, open-label, single-arm, phase 3 trials.

BACKGROUND: A ring-shaped, contraceptive vaginal system designed to last 1 year (13 cycles) delivers an average of 0·15 mg segesterone acetate and 0·013 mg ethinylestradiol per day. We evaluated the efficacy of this contraceptive vaginal system and return to menses or pregnancy after use. METHODS: In two identically designed, multicentre, open-label, single-arm, phase 3 trials (one at 15 US academic and community sites and one at 12 US and international academic and community sites), participants followed a 21-days-in, 7-days-out segesterone acetate and ethinylestradiol contraceptive vaginal system schedule for up to 13 cycles. Participants were healthy, sexually active, non-pregnant, non-sterilised women aged 18-40 years. Women were cautioned that any removals during the 21 days of cyclic use should not exceed 2 h, and used daily paper diaries to record vaginal system use. Consistent with regulatory requirements for contraceptives, we calculated the Pearl Index for women aged 35 years and younger, excluding adjunctive contraception cycles, as the primary efficacy outcome measure. We also did intention-to-treat Kaplan-Meier life table analyses and followed up women who did not use hormonal contraceptives or desired pregnancy after study completion for 6 months for return to menses or pregnancy. The trials are registered with ClinicalTrials.gov, numbers NCT00455156 and NCT00263341. FINDINGS: Between Dec 19, 2006, and Oct 9, 2009, at the 15 US sites, and between Nov 1, 2006, and July 2, 2009, at the 12 US and international sites we enrolled 2278 women. Our overall efficacy analysis included 2265 participants (1130 in the US study and 1135 in the international study) and 1303 (57·5%) participants completed up to 13 cycles. The Pearl Index for the primary efficacy group was 2·98 (95% CI 2·13-4·06) per 100 woman-years, and was well within the range indicative of efficacy for a contraceptive under a woman's control. The Kaplan-Meier analysis revealed the contraceptive vaginal system was 97·5% effective, which provided further evidence of efficacy. Pregnancy occurrence was similar across cycles. All 290 follow-up participants reported return to menses or became pregnant (24 [63%] of 38 women who desired pregnancy) within 6 months. INTERPRETATION: The segesterone acetate and ethinylestradiol contraceptive vaginal system is an effective contraceptive for 13 consecutive cycles of use. This new product adds to the contraceptive method mix and the 1-year duration of use means that women do not need to return to the clinic or pharmacy for refills every few months. FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health, the US Agency for International Development, and the WHO Reproductive Health Research Department.