Benchmark pregnancy rates and the assessment of post-coital contraceptives: an update

Maximizing the effectiveness of 1.5 mg levonorgestrel for emergency contraception: The case for precoital use

Objectives

U.S. and World Health Organization Selected Practice Recommendations for Contraceptive Use state people may have an advanced supply of emergency contraception (EC) to minimize treatment delays. We sought to characterize the potential improvement in effectiveness of 1.5 mg levonorgestrel (LNG-EC) if it were taken up to a few hours before unprotected sex.

Study design

We expanded on an existing mathematical model for the maximum attainable effectiveness of LNG-EC, assuming it exclusively works to disrupt ovulation, and compared results with point estimates from nine studies when it was taken up to 72 hours after sex. We then modelled how effectiveness might have improved if subjects had taken LNG-EC up to 3 hours before sex.

Results

Taking LNG-EC immediately after sex could potentially reduce the risk of unintended pregnancy by 91%. However, population-average maximum attainable effectiveness levels ranged from just 49% to 67% when accounting for the distributions of postcoital treatment delays in the example studies. If half the subjects had taken it 3 hours before sex, then maximum effectiveness levels would have ranged from 70% to 81%.

Conclusions

At the individual level, taking LNG-EC a few hours before sex is a logical extension of Selected Practice Recommendations regarding an advanced supply of EC and, based on our modeling, should be advocated for people who can reasonably anticipate an unprotected sex act. In the absence of more clinical data, however, people should not routinely rely on precoital use of LNG-EC to prevent pregnancy unless modern, effective contraceptives are inaccessible to them.

Implications

Based on mathematical modeling, individuals who anticipate needing to take LNG-EC for an impending unprotected act of sex could further reduce their chance of an undesired pregnancy by taking it a few hours in advance.

Environmental statistics and experience shape risk-taking across adolescence

Adolescents are often portrayed as reckless risk-takers because of their immature brains. Recent research has cast doubt on this portrayal, identifying the environment as a moderator of risk-taking. However, the key features of environments that drive risk-taking behaviors are often underspecified. We call for greater attention to the environment by drawing on research showing that its statistical structure impacts future risk-taking as people learn from outcomes they experience after taking a risk. This opinion shows that adolescents are unlikely to experience harm from many risks because environmental statistics are skewed and favor safe experiences. Environmental statistics and experience suggest entry points for policy interventions by carefully timing risk warnings and leveraging peers' potential to shape the statistics of rewarding experiences.

Emergency contraception - A review

Emergency contraception (EC), or postcoital contraception, is a therapy aimed at preventing unintended pregnancy after an act of unprotected or under-protected sexual intercourse. Options include both emergency contraceptive pills (most commonly containing levonorgestrel or ulipristal acetate) and insertion of an intrauterine device. The aim of this paper is to summarize current evidence surrounding the use of emergency contraceptives and to present an evidence-based approach to EC provision. Emergency contraception is a safe and effective option in preventing unwanted pregnancy, irrespective of age, weight, or breastfeeding status. Efforts should be made to increase their availability, as well as knowledge of these methods, both among patients and healthcare providers.

The role of legal medicine professionals in preventing pregnancy and sexually transmitted infections among female victims of sexual assault

Sexual violence can have an overwhelming impact on the victim's physical and mental health; the consequences include unintended pregnancy and sexually transmitted infections (STIs). Therefore, the examiners must assess victims for possible pregnancy and sexually transmitted infections as a part of the sexual assault examination. This article aims to orient the medico-legal examiners towards their role in preventing unintended pregnancy and sexually transmitted infections among victims of sexual assault. Prompt detection of pregnancy or STIs is critical, as any delay would adversely affect the successful administration of emergency contraception and post-exposure prophylaxis (PEP) against human immunodeficiency virus (HIV) and other sexually transmitted infections.

Society of Family Planning Clinical Recommendation: Emergency contraception

Emergency contraception (EC) refers to several contraceptive options that can be used within a few days after unprotected or under protected intercourse or sexual assault to reduce the risk of pregnancy. Current EC options available in the United States include the copper intrauterine device (IUD), levonorgestrel (LNG) 52 mg IUD, oral LNG (such as Plan B One-Step, My Way, Take Action), and oral ulipristal acetate (UPA) (ella). These clinical recommendations review the indications, effectiveness, safety, and side effects of emergency contraceptive methods; considerations for the use of EC by specific patient populations and in specific clinical circumstances and current barriers to emergency contraceptive access. Further research is needed to evaluate the effectiveness of LNG IUDs for emergency contraceptive use; address the effects of repeated use of UPA at different times in the same menstrual cycle; assess the impact on ovulation of initiating or reinitiating different regimens of regular hormonal contraception following UPA use; and elucidate effective emergency contraceptive pill options by body mass indices or weight.

High incidence of sexual dysfunction and timed intercourse was found only in infertile males who with known impairment of sperm quality for a long period: evidence from a hospital-based cross-sectional study

BACKGROUND

Infertile men with higher sexual dysfunction risk and increased psychological burden, were also associated with more inclined to timed intercourse. Decreased semen quality may have adverse effects on male sexual function. However, it is also likely that many of these sequences do not play a direct role, those negative consequences may depend mainly on the later failed attempting pregnancy. Research is limited in this area.

METHODS

This cross-sectional study was based on a group of 509 men who were assessed for couple's infertility at the First Hospital of Jilin University between June 2021 and October 2021. All the men completed a comprehensive questionnaire, and then were divided in two groups. Group A included patients who either never received a routine infertility work-up or done so recently within the last 6 months. Group B included patients who previously received a sperm quality assessment at least 6 months or more prior. Patients were further categorized into three subgroups according to the severity of the decreases in their sperm parameters: severe, mild-moderate, and normozoospermic.

RESULTS

The prevalence of erectile dysfunction was higher in Group B Mild-Moderate and Group B Severe in comparison to Group A (OR=1.86 [1.07-3.24], P = 0.027; OR=5.312 [2.69-10.49], P < 0.001, respectively). No significant differences were found between Group A and Group B-normozoospermic. Similar results were observed in the prevalence of premature ejaculation between the groups. Timed intercourse was seen in 11.8% (20/170) of men in Group A and 16.2% (19/117) in Group B-normozoospermic. It was more commonly practiced among infertile men in Group B-Mild-Moderate and Group B Severe, as 28.2% (44/156) and 25.7% (17/66) of these couples had attempted to conceive through timed intercourse (P < 0.001).

CONCLUSIONS

Our findings indicate that the severity of sperm quality impairment was negatively associated with sexual dysfunction only in infertile men who with known impairment of sperm quality for a long period. Timed intercourse was more common among these couples. For those individuals had never test their sperm quality, although more than half of these patients showed a decrease in sperm quality, the incidence of sexual dysfunction is relatively low and were comparable to those men examined previously known as normozoospermic.

Perspective Chapter: Modern Birth Control Methods

This chapter focuses on various modern birth control methods, including combined oral contraceptives, progestogen-only pills, progestogen-only injectables, progestogen-only implants, intrauterine devices, barrier contraceptives, and emergency contraceptive pills. Each contraceptive method is covered in detail, including mechanism of action, effectiveness, health benefits, advantages, disadvantages, risks, and side-effects.

Hexavalent sperm-binding IgG antibody released from vaginal film for development of potent on-demand nonhormonal female contraception

Nearly half of all pregnancies in the United States are unintended due to millions of women avoiding available hormonal contraceptive methods as a result of real and/or perceived side effects associated with the use of exogenous hormones. Topical vaginal delivery of antisperm monoclonal antibodies that could agglutinate sperm into clusters too large to penetrate mucus and prevent sperm from reaching the egg represents a potentially safe and potent mechanism for nonhormonal contraception. We report here the engineering of a vaginal film loaded with hexavalent (i.e., 6 Fab) antisperm IgG, made using GMP manufacturing processes, that possesses significantly superior agglutination potency than the parent IgG, enabling potent on-demand nonhormonal contraception via effectively agglutinating all human sperm within minutes.

Nonhormonal products for on-demand contraception are a global health technology gap; this unmet need motivated us to pursue the use of sperm-binding monoclonal antibodies to enable effective on-demand contraception. Here, using the cGMP-compliant Nicotiana-expression system, we produced an ultrapotent sperm-binding IgG antibody possessing 6 Fab arms per molecule that bind a well-established contraceptive antigen target, CD52g. We term this hexavalent antibody “Fab-IgG-Fab” (FIF). The Nicotiana-produced FIF had at least 10-fold greater sperm-agglutination potency and kinetics than the parent IgG, while preserving Fc-mediated trapping of individual spermatozoa in mucus. We formulated the Nicotiana-produced FIF into a polyvinyl alcohol–based water-soluble contraceptive film and evaluated its potency in reducing progressively motile sperm in the sheep vagina. Two minutes after vaginal instillation of human semen, no progressively motile sperm were recovered from the vaginas of sheep receiving FIF Film. Our work supports the potential of multivalent contraceptive antibodies to provide safe, effective, on-demand nonhormonal contraception.

Rates of pregnancy among levonorgestrel and copper intrauterine emergency contraception initiators: Implications for backup contraception recommendations

OBJECTIVE

This study assessed the timing, frequency, use of backup method and 1-month pregnancy rates among individuals who had an intrauterine device (IUD) placed as emergency contraception and reported intercourse within 7 days post-placement.

STUDY DESIGN

In this secondary analysis of a randomized control trial of IUDs for emergency contraception, 518 individuals reporting unprotected intercourse in the preceding 5 days had a 52 mg levonorgestrel intrauterine system (IUS) or 380 mm2 copper IUD placed outside the first week of their menstrual cycle. All participants were advised to use backup contraception for 7 days. We assessed pregnancy status 1 month after placement by urine testing or, when not available, by survey responses and electronic health record review.  Participants reported whether their first sexual activity after device placement occurred within 7 days of their placement, the frequency of intercourse and whether they used backup contraception.

RESULTS

Rapid return to sexual activity was common and use of backup contraception was rare, regardless of type of IUD placed. Of participants who resumed penile-vaginal intercourse in the first month, most (286/446, 64.1%) participants reported intercourse within 7 days of IUD placement; only 16.4% (74/446) used condoms or withdrawal. No pregnancies occurred among users of the levonorgestrel IUS who reported intercourse within 7 days of placement (0/138, 0.0%, 95% CI 0.0%, 2.6%) nor among users of the 380mm2 copper IUD (0/148, 0.0%, 95% CI 0.0%, 2.5%).

CONCLUSION

Pregnancy rates are low after placement of an IUD for emergency contraception, even among the many who resume intercourse within days following IUD placement without use of backup contraception.

IMPLICATIONS

Clinical guidelines should facilitate access to contraception, including elimination of unnecessary recommendations for backup contraception or abstinence in the 7 days following 52 mg levonorgestrel intrauterine system.

Engineering sperm-binding IgG antibodies for the development of an effective nonhormonal female contraception

Many women risk unintended pregnancy because of medical contraindications or dissatisfaction with contraceptive methods, including real and perceived side effects associated with the use of exogenous hormones. We pursued direct vaginal delivery of sperm-binding monoclonal antibodies (mAbs) that can limit progressive sperm motility in the female reproductive tract as a strategy for effective nonhormonal contraception. Here, motivated by the greater agglutination potencies of polyvalent immunoglobulins but the bioprocessing ease and stability of immunoglobulin G (IgG), we engineered a panel of sperm-binding IgGs with 6 to 10 antigen-binding fragments (Fabs), isolated from a healthy immune-infertile woman against a unique surface antigen universally present on human sperm. These highly multivalent IgGs (HM-IgGs) were at least 10- to 16-fold more potent and faster at agglutinating sperm than the parent IgG while preserving the crystallizable fragment (Fc) of IgG that mediates trapping of individual spermatozoa in mucus. The increased potencies translated into effective (>99.9%) reduction of progressively motile sperm in the sheep vagina using as little as 33 μg of the 10-Fab HM-IgG. HM-IgGs were produced at comparable yields and had identical thermal stability to the parent IgG, with greater homogeneity. HM-IgGs represent not only promising biologics for nonhormonal contraception but also a promising platform for engineering potent multivalent mAbs for other biomedical applications.

Contraceptive Needs Among Women Recently Incarcerated at a Rural Appalachian Jail

Background: Incarceration is associated with negative sexual and reproductive health outcomes. We examined contraceptive needs among women incarcerated at a rural Appalachian jail with emphasis on pregnancy history, recent contraceptive use, and current and near-future contraceptive needs. Materials and Methods: A survey was administered to newly incarcerated women at a jail in Southwest Virginia. It included questions about (1) prior pregnancies; (2) pregnancy intentions, contraceptive use, and sexual activity in the 3 months before jail; (3) unprotected sex in the 5 days before jail; (4) interest in contraceptive education and access during incarceration; and (5) post-release sexual activity, pregnancy, and contraceptive plans. Results: One hundred ninety-three women completed surveys. Analyses focused on the 95 at risk for pregnancy. Fifty-eight percent of prior pregnancies on which women provided intention information were unintended, with 74% of respondents reporting at least 1 such pregnancy. Ninety-four percent of women reported vaginal intercourse during the 3 months before jail. Only 46% of those who did not want to get pregnant reported consistent contraceptive use. Condoms and withdrawal were the most common methods used. Forty percent of women were eligible for emergency contraception (EC). Most (78%) participants anticipated sex with a man within 6 months of release, and most (63%) did not want to become pregnant within a year of release. Almost half (47%) expressed interest in receiving birth control while in jail. Conclusions: Results support the need to offer women EC on incarceration, family planning education during confinement, and effective birth control before release.

Reducing the Prevalence of Alcohol-Exposed Pregnancies in the United States: A Simulation Modeling Study

BACKGROUND

Public health efforts to prevent alcohol-exposed pregnancies (AEPs) primarily focus on promoting abstinence from alcohol among women if pregnant or seeking pregnancy and using effective contraception to prevent unintended pregnancies if consuming alcohol. Little is known about how programs to improve adherence to these recommendations would affect the prevalence of AEPs.

METHODS

We developed an individual-based simulation model of US women of reproductive age to project the prevalence of AEPs under different public health strategies. The model varies each woman's risk of an AEP over time depending on fertility, contraceptive use, awareness of pregnancy, sexual activity, and drinking patterns. We used the 2013-2015 National Survey on Family Growth data set to parameterize the model.

RESULTS

We estimate that 54% (95% uncertainty interval: 48%-59%) of pregnancies that result in a live birth in the United States are exposed to alcohol, 12% (10%-15%) are ever exposed to ≥5 alcoholic drinks in a week, and 3.0% (1.3%-4.2%) to ≥9 drinks. Unintended pregnancies (either due to contraceptive failure or sex without contraceptives) account for 80% (75%-87%) of pregnancies unknowingly exposed to alcohol. We project that public health efforts that focus only on promoting alcohol abstinence among women who are aware of their pregnancy or seeking pregnancy could reduce the prevalence of AEPs by at most 42% (36%-48%). Augmenting this strategy with efforts to avert unintended pregnancies could yield an 80% (73%-86%) reduction in the prevalence of AEPs.

CONCLUSIONS

Promoting alcohol abstinence among women who are aware of their pregnancy or seeking pregnancy offers limited potential to reduce the prevalence of AEPs. Programs to avert unintended pregnancies are essential to achieve more substantial reductions in AEPs in the United States.

Female Voice-Related Sexual Attractiveness to Males: Does it Vary With Different Degrees of Conception Likelihood?

Previous investigations have found that female voice-related attractiveness to males increases when both conception likelihood (CL) and voice fundamental frequency (f_o) are elevated. To test this hypothesis, we conducted a perceptual experiment where 78 heterosexual males rated sexual attractiveness of 9 female voice samples, recorded at menstrual, follicular and luteal phases of the menstrual cycle under two double-blinded randomly allocated conditions: a natural menstrual cycle (placebo condition) and when using an oral contraceptive pill (OCP condition). The voice samples yielded a total of 54 stimuli that were visually sorted and rated using Visor software. Concentrations of estrogens, progesterone and testosterone were analyzed, and measurements of speaking fundamental frequency (sf_o) and its standard deviation (sf_oSD), f_o derivative (df_o) and f_o slope were made. A multilevel ordinal logistic regression model nested in listeners and in females, and adjusted by phase and condition, was carried out to assess the association between ratings and: (1) phases and conditions; (2) sex steroid hormonal concentrations; and (3) voice parameters. A high probability of obtaining high ratings of voice sexual attractiveness was found for: (1) menstrual phase of placebo use and follicular phase of OCP use; (2) for low estradiol to progesterone ratio and testosterone concentrations; and (3) for low df_o. The latter showed a moderate statistical association with ratings of high attractiveness, as compared with the small association found for the remaining variables. It seems that the voice is a weak cue for female CL. Female sexual attraction to males may be a consequence of what females do in order to regulate their extended sexuality across the menstrual cycle rather than of estrus cues, the use of paralinguistic speech patterns being an example.

Perceived likelihood of becoming pregnant and contraceptive use: Findings from population-based surveys in Côte d'Ivoire, Nigeria, and Rajasthan, India

OBJECTIVE

Advancing reproductive autonomy requires targeted strategies and interventions that address barriers to contraceptive use. The primary objective of this study is to investigate whether perceptions of low pregnancy likelihood are associated with lower likelihood of using contraception among presumably fecund, sexually active women.

STUDY DESIGN

We used population-based survey data of reproductive age women at risk of pregnancy collected in 2018 from Côte d'Ivoire (N = 1447), Nigeria (N = 4110), and Rajasthan, India (N = 1994). To assess one's perceived biological likelihood of pregnancy, we used 2 measures: likelihood following a single act of sex without contraception and likelihood following 1 year of regular sex without contraception. Response options included: definitely yes, maybe yes, maybe no, definitely no, and do not know. We conducted multivariable logistic regression to assess the relationship between each perception measure with odds of contraceptive use separately by country.

RESULTS

Perceived chance of definitely or maybe becoming pregnant after one act of sex without contraception ranged from 54.0% to 55.0% in Nigeria and Rajasthan to 80.0% in Côte d'Ivoire, while it was higher for regular sex without contraception (76.0%-85.1%). Multivariable results indicate that perceptions of pregnancy likelihood were associated with contraceptive use among presumably fecund women, with a stronger relationship observed in relation to cumulative likelihood (odds ratio 0.1-0.6) than likelihood after one act (odds ratio 0.4-0.8) and a dose-response pattern by strength of perceived chance.

CONCLUSIONS

Results indicate that women's use of contraception in low-resource settings is associated with their perceived likelihood of becoming pregnant after unprotected sex.

IMPLICATIONS

Findings suggest that understanding women's perceived likelihood of pregnancy may aid in the development of interventions to help women achieve their reproductive goals.

Engineering tetravalent IgGs with enhanced agglutination potencies for trapping vigorously motile sperm in mucin matrix

Multivalent antibodies such as sIgA can crosslink motile entities such as sperm and bacteria, creating agglomerates that are too large to permeate the dense mucin matrix in mucus, a process commonly referred to as immune exclusion. Unfortunately, sIgA remains challenging to produce in large quantities, and easily aggregates, which prevented their use in clinical applications. To develop sIgA-like tetravalent antibodies that are stable and can be easily produced in large quantities, we designed two IgGs possessing 4 identical Fab domains, with the Fabs arranged either in serial or in the diametrically opposite orientation. As a proof-of-concept, we engineered these tetravalent IgG constructs to bind a ubiquitous sperm antigen using a Fab previously isolated from an immune infertile woman. Both constructs possess at least 4-fold greater agglutination potency and induced much more rapid sperm agglutination than the parent IgG, while exhibiting comparable production yields and identical thermostability as the parent IgG. These tetravalent IgGs offer promise for non-hormonal contraception and underscores the multimerization of IgG as a promising strategy to enhance antibody effector functions based on immune exclusion.

Shifts in Female Facial Attractiveness during Pregnancy

It has been proposed that women’s physical attractiveness is a cue to temporal changes in fertility. If this is the case, we should observe shifts in attractiveness during pregnancy—a unique physiological state of temporal infertility. The aim of this study was to examine how women’s facial attractiveness changes during the subsequent trimesters of pregnancy and how it compares to that of nonpregnant women. Sixty-six pictures of pregnant women (22 pictures per trimester) and 22 of nonpregnant women (a control group) were used to generate four composite portraits, which were subsequently assessed for facial attractiveness by 117 heterosexual men. The results show considerable differences between facial attractiveness ratings depending on the status and progress of pregnancy. Nonpregnant women were perceived as the most attractive, and the attractiveness scores of pregnant women decreased throughout the course of pregnancy. Our findings show that facial attractiveness can be influenced by pregnancy and that gestation, even at its early stages, affects facial attractiveness. Considerable changes in women’s physiology that occur during pregnancy may be responsible for the observed effects.

Simplifying contraception requirements for iPLEDGE: A decision analysis

BACKGROUND

For persons of childbearing potential prescribed isotretinoin, the iPLEDGE program requires use of 2 simultaneous methods of contraception or commitment to abstinence.

OBJECTIVE

To model the relative effectiveness of a variety of contraception strategies for patients taking isotretinoin, including those that are acceptable according to iPLEDGE.

METHODS

We performed a decision analysis modeling the estimated rate of pregnancy with various contraception strategies during a typical 6-month course of isotretinoin.

RESULTS

Tier 1 contraception options (eg, subdermal hormonal implant, intrauterine devices) each had effectiveness of >99.5% alone. When combined with a secondary form of contraception, tier 2 contraception options (eg, depot medroxyprogesterone injections, combined oral contraceptives) each had effectiveness >99%.

LIMITATIONS

Sensitivity analyses were conducted to evaluate the impact of uncertain parameters on the results.

CONCLUSION

There may be opportunities to simplify iPLEDGE by recognizing the high effectiveness of tier 1 contraception options and increasing use of secondary forms of contraception among those using tier 2 contraception options as their primary form of contraception. Future studies are needed to understand the most effective strategies in clinical practice to prevent unintended pregnancy for patients taking isotretinoin to improve outcomes and provide patient-centered care.

No. 329-Canadian Contraception Consensus Part 4 of 4 Chapter 9: Combined Hormonal Contraception

OBJECTIVE

To provide guidelines for health care providers on the use of contraceptive methods to prevent pregnancy and on the promotion of healthy sexuality.

OUTCOMES

Overall efficacy of cited contraceptive methods, assessing reduction in pregnancy rate, safety, and side effects; the effect of cited contraceptive methods on sexual health and general well-being; and the availability of cited contraceptive methods in Canada.

EVIDENCE

Medline and the Cochrane Database were searched for articles in English on subjects related to contraception, sexuality, and sexual health from January 1994 to December 2015 in order to update the Canadian Contraception Consensus published February-April 2004. Relevant Canadian government publications and position papers from appropriate health and family planning organizations were also reviewed.

VALUES

The quality of the evidence is rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. Recommendations for practice are ranked according to the method described in this report.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Hormonal Contraceptives, Female Sexual Dysfunction, and Managing Strategies: A Review

In recent decades, hormonal contraceptives (HC) has made a difference in the control of female fertility, taking an unequivocal role in improving contraceptive efficacy. Some side effects of hormonal treatments have been carefully studied. However, the influence of these drugs on female sexual functioning is not so clear, although variations in the plasma levels of sexual hormones could be associated with sexual dysfunction. Permanent hormonal modifications, during menopause or caused by some endocrine pathologies, could be directly related to sexual dysfunction in some cases but not in all of them. HC use seems to be responsible for a decrease of circulating androgen, estradiol, and progesterone levels, as well as for the inhibition of oxytocin functioning. Hormonal contraceptive use could alter women's pair-bonding behavior, reduce neural response to the expectation of erotic stimuli, and increase sexual jealousy. There are contradictory results from different studies regarding the association between sexual dysfunction and hormonal contraceptives, so it could be firmly said that additional research is needed. When contraceptive-related female sexual dysfunction is suspected, the recommended therapy is the discontinuation of contraceptives with consideration of an alternative method, such as levonorgestrel-releasing intrauterine systems, copper intrauterine contraceptives, etonogestrel implants, the permanent sterilization of either partner (when future fertility is not desired), or a contraceptive ring.

Estimating the Prevalence of United States Women with Alcohol-exposed Pregnancies and Births

AIMS

Researchers at the U.S. Centers for Disease Control and Prevention (CDC) recently estimated the number of women at risk for alcohol-exposed pregnancies (AEPs) as 3.3 million per month. The number of women at risk was widely interpreted as the actual number of AEPs. The actual number of AEPs may be easier to interpret and may be more a more relevant public health metric for evaluating efforts to reduce AEPs. We estimated the expected actual number of AEPs among U.S. women 15-44 years of age and the expected actual number of alcohol-exposed births (AEBs).

METHODS

Like the CDC researchers, we used data about women aged 15-44 years who were neither pregnant nor sterile from the 2011-2013 National Survey of Family Growth. We identified women who had had sex without contraception in the last 4 weeks and reported binge drinking or drinking on more than 7 of the last 30 days. We then estimated the expected actual number of AEPs and AEBs, accounting for the chances of becoming pregnant and for pregnancy outcomes (birth, miscarriage, and abortion). We also conducted sensitivity analyses with varying assumptions.

RESULTS

Estimated prevalences of AEPs and AEBs were 1.2% (95% confidence interval, 0.9-1.7) and 0.8% (95% confidence interval, 0.5-1.2), respectively. During a 1-month period, we estimate 731,000 U.S. women had AEPs and 481,000 resulted in AEBs. Sensitivity analyses indicate expected actual AEP estimates ranging from 104,000 to 1,242,000 and AEBs from 79,000 to 816,000.

CONCLUSIONS

Under our assumptions, the estimated expected actual number of AEPs is 2.5 million less than the CDC estimate of the number at risk of an AEP. By using evidence-informed assumptions for the chances of becoming pregnant and common pregnancy outcomes, our estimate of the expected actual number of AEPs is only 22% as large as the CDC's estimate of number at risk, and our estimate of expected actual number of AEBs only 15% as large. The evidence-informed assumptions used here should inform future efforts to estimate expected actual numbers of AEPs and AEBs.

Pharmacologic Therapies in Women's Health: Contraception and Menopause Treatment

Female hormones play a significant role in the etiology and treatment of many women's health conditions. This article focuses on the common uses of hormonal therapy. When prescribing estrogen-containing regimens throughout the span of a woman's life, the risks are similar (ie, cardiovascular risk and venous thromboembolism), but the degree of risk varies significantly depending on a woman's particular set of risk factors and the details of the hormone regimen. In addition to estrogens and progestogens, this article also touches on the use of selective steroid receptor modulators in emergency contraception and in treatment of menopause symptoms.

Personalised estimation of a woman's most fertile days

OBJECTIVES

We propose a new, personalised approach of estimating a woman's most fertile days that only requires recording the first day of menses and can use a smartphone to convey this information to the user so that she can plan or prevent pregnancy.

METHODS

We performed a retrospective analysis of two cohort studies (a North Carolina-based study and the Early Pregnancy Study [EPS]) and a prospective multicentre trial (World Health Organization [WHO] study). The North Carolina study consisted of 68 sexually active women with either an intrauterine device or tubal ligation. The EPS comprised 221 women who planned to become pregnant and had no known fertility problems. The WHO study consisted of 706 women from five geographically and culturally diverse settings. Bayesian statistical methods were used to design our proposed method, Dynamic Optimal Timing (DOT). Simulation studies were used to estimate the cumulative pregnancy risk.

RESULTS

For the proposed method, simulation analyses indicated a 4.4% cumulative probability of pregnancy over 13 cycles with correct use. After a calibration window, this method flagged between 11 and 13 days when unprotected intercourse should be avoided per cycle. Eligible women should have cycle lengths between 20 and 40 days with a variability range less than or equal to 9 days.

CONCLUSIONS

DOT can easily be implemented by computer or smartphone applications, allowing for women to make more informed decisions about their fertility. This approach is already incorporated into a patent-pending system and is available for free download on iPhones and Androids.

Population-based evaluation of the effectiveness of two regimens for emergency contraception

OBJECTIVE

To estimate and compare the effectiveness of the levonorgestrel and Yuzpe regimens for hormonal emergency contraception in routine clinical practice.

METHODS

A retrospective population-based study included women who accessed emergency contraceptives for immediate use prescribed by community pharmacists in British Columbia, Canada, between December 2000 and December 2002. Linked administrative healthcare data were used to discern the timings of menses, unprotected intercourse, and any pregnancy-related health services. A panel of experts evaluated the compatibility of observed pregnancies with the timing of events. The two regimens were compared with statistical adjustments for potential confounding.

RESULTS

Among 7493 women in the cohort, 4470 (59.7%) received levonorgestrel and 3023 (40.3%) the Yuzpe regimen. There were 99 (2.2%) compatible pregnancies in the levonorgestrel group and 94 (3.1%) in the Yuzpe group (P=0.017). The estimated odds ratio for levonorgestrel compared with the Yuzpe regimen after adjusting for potential confounders was 0.64 (95% confidence interval 0.47-0.87). Against an expected pregnancy rate of approximately 5%, the relative and absolute risk reductions were 56.0% and 2.8%, respectively, for levonorgestrel and 36.7% and 1.8% for the Yuzpe regimen.

CONCLUSION

The levonorgestrel regimen is more effective than the Yuzpe regimen in routine use. The data suggest that both regimens are less effective than has been observed in randomized trials.

Injectable agents for pre-exposure prophylaxis: lessons learned from contraception to inform HIV prevention

PURPOSE OF REVIEW

Long-acting injectable (LAI) forms of preexposure prophylaxis (PrEP) are in clinical trials, generating much hope for HIV prevention. But this is not the first time that an injectable form of preventive medication has emerged: the contraceptive agent depomedroxyprogesterone acetate (DMPA) has an important precedent. DMPA's long journey, its initial reception, and ongoing implementation challenges can help inform the field of HIV prevention as we plan for approval, acceptance, and scale-up of LAI-PrEP.

RECENT FINDINGS

DMPA faced a long regulatory journey in the USA, with a lag of 25 years from initial application (1967) to approval (1992). Acceptance after introduction was rapid, but challenges hampered scale-up. Specific lessons learned include that extensive acceptability work is needed in parallel to product development. Also, low continuation rates, challenges with timing of initiation, and difficulty ensuring access for the most vulnerable populations have limited DMPA's impact. A new subcutaneous formulation presents opportunities for administration outside of clinical settings and for self-administration.

SUMMARY

Those involved in LAI-PrEP development and those who plan to be involved in its future implementation must consider these lessons and possible solutions from DMPA to ensure a successful future for this new HIV prevention modality.