Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation

Pharmacodynamic evaluation of the etonogestrel contraceptive implant initiated midcycle with and without ulipristal acetate: An exploratory study

OBJECTIVE

To estimate the incidence of ovulation suppression within five days of etonogestrel 68 mg implant insertion in the presence of a dominant follicle with and without same-day ulipristal acetate.

STUDY DESIGN

This single site non-masked, exploratory randomized trial recruited people age 18-35 years with regular menstrual cycles, no pregnancy risk, and confirmed ovulatory function. We initiated transvaginal ultrasound examinations on menstrual day 7-9 and randomized participants 1:1 to etonogestrel implant alone or with concomitant ulipristal acetate 30 mg oral when a dominant follicle reached ≥14 mm in diameter. We completed daily sonography and serum hormone levels for up to seven days or transitioned to labs alone if sonographic follicular rupture occurred. We defined ovulation as follicular rupture followed by progesterone >3 ng/mL. We calculated point estimates, risk ratios and 95% confidence intervals for ovulation for each group. Ovulation suppression of ≥44% in either group (the follicular rupture suppression rate with oral levonorgestrel emergency contraception), would prompt future method testing.

RESULTS

From October 2020 to October 2022, we enrolled 40 people and 39 completed primary outcome assessments: 20 with etonogestrel implant alone (mean follicular size at randomization: 15.2 mm ± 0.9 mm) and 19 with etonogestrel implant + ulipristal acetate (mean follicular size at randomization: 15.4 mm ± 1.2 mm, p = 0.6). Ovulation suppression occurred in 13 (65%) of etonogestrel implant-alone participants (Risk ratio 0.6 (95% CI: 0.3, 1.1), p = 0.08) and seven (37%) of implant + ulipristal acetate participants.

CONCLUSIONS

Ovulation suppression of the etonogestrel implant alone exceeds threshold testing for future research while the implant + ulipristal acetate does not.

IMPLICATIONS

Data are lacking on midcycle ovulation suppression for the etonogestrel implant with and without oral ulipristal acetate. In this exploratory study, ovulation suppression occurred in 65% of implant participants and 37% of implant + ulipristal acetate participants. Ovulation suppression of the implant alone exceeds threshold testing for future emergency contraception research.

The Levonorgestrel-Releasing Intrauterine Device as Emergency Contraception: Re-examining the Data

Emergency contraception methods that also deliver ongoing contraception provide the most effective options for individuals hoping to prevent pregnancy after unprotected intercourse. Although the copper intrauterine device (IUD) provides the most effective option for emergency contraception because the device prevents pregnancy when placed before implantation and offers long-acting contraception, uptake by patients has been limited. Recently, the Society of Family Planning issued new guidance recommending the levonorgestrel IUD (LNG-IUD) as an emergency contraception option along with the copper IUD. Here, we review evidence related to this recommendation and conclude that the available data do not support use of the LNG-IUD for emergency contraception. We discuss the mechanisms of action of emergency contraception methods and how these concepts interface with the current political and social landscape of contraception and abortion care. We describe limitations of the existing evidence supporting use of the LNG-IUD as emergency contraception and highlight the critical research needed to establish the device as a highly effective method of emergency contraception.

An overview of contraception in women with obesity

The use of safe and effective contraception is essential for preventing unplanned pregnancy in women of all body sizes. When counseling women with obesity about contraception, it is important to consider the pharmacokinetic alterations of obesity on various modern contraceptive methods. However, evidence is reassuring that most contraceptive methods are safe and effective in women with obesity. Individual countries and the World Health Organization have published Medical Eligibility Criteria to guide contraceptive selection in women with medical issues including obesity. When choosing contraception, specific risks of the method relative to any underlying medical disorders must also be balanced against the risks of unintended pregnancy in this group.

Gene Expression Changes in the Ovary Mediate Non-Anovulatory Mechanisms of Contraception with Levonorgestrel

BACKGROUND

Emergency contraception with levonorgestrel (LNG) is a viable option to prevent unintended pregnancies. Although the efficacy of LNG as an anovulatory agent decreases as treatment approaches ovulation, it still provides some contraceptive benefits.

AIM

To better understand the contraceptive mechanisms of LNG in ovulatory subjects.

METHODS

We conducted a study on Wistar rats that received a single dose of LNG (0.01 or 0.05 mg/kg) on the morning of proestrus before ovulation and evaluated its effects on ovarian gene expression, ovulation, and implantation.

RESULTS

Our findings showed changes in the expression of genes involved in follicular development and oocyte quality. Pregnancy rates - as an indicator of ovulation - and embryo implantation were significantly lower than those in the control group.

CONCLUSIONS

This study suggests that LNG alters regulatory factors in the ovary that are essential for the development of competent fertilizable oocytes, highlighting the non-anovulatory mechanisms by which levonorgestrel may regulate fertility and suggesting that it could be a novel observation that contributes to the understanding of emergency contraception in humans.

Oral emergency contraception with levonorgestrel plus piroxicam: a randomised double-blind placebo-controlled trial

BACKGROUND

Levonorgestrel, a standard drug for emergency contraception (EC), is not effective if administered post-ovulation. A cyclo-oxygenase inhibitor could contribute synergistic effects. We investigated whether a single 40 mg oral dose of piroxicam as co-treatment with levonorgestrel improved emergency contraceptive efficacy.

METHODS

This was a randomised double-blind placebo-controlled trial carried out in a major community sexual and reproductive health service in Hong Kong. Women who required levonorgestrel EC within 72 h of unprotected sexual intercourse were recruited and block-randomised in a 1:1 ratio to receive a single supervised dose of levonorgestrel 1·5 mg plus either piroxicam 40 mg or placebo orally. Group assignment was concealed in opaque envelopes and masked to the women, clinicians, and investigators. At follow-up 1-2 weeks after the next expected period, the pregnancy status was noted by history or pregnancy test. The primary efficacy outcome was the proportion of pregnancies prevented out of those expected based on an established model. All women randomised to receive the study drug and who completed the follow-up were analysed. The trial was registered with ClinicalTrials.gov, NCT03614494.

FINDINGS

860 women (430 in each group) were recruited between Aug 20, 2018, and Aug 30, 2022. One (0·2%) of 418 efficacy-eligible women in the piroxicam group were pregnant, compared with seven (1·7%) of 418 in the placebo group (odds ratio 0·20 [95% CI 0·02-0·91]; p=0·036). Levonorgestrel plus piroxicam prevented 94·7% of expected pregnancies compared with 63·4% for levonorgestrel plus placebo. We noted no significant difference between the two groups in the proportion of women with advancement or delay of their next period, or in the adverse event profile.

INTERPRETATION

Oral piroxicam 40 mg co-administered with levonorgestrel improved efficacy of EC in our study. Piroxicam co-administration could be considered clinically where levonorgestrel EC is the option of choice.

FUNDING

None.

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.

Emergency Contraception: Access and Challenges at Times of Uncertainty

BACKGROUND

The UN Commission on Life-Saving Commodities for Women's and Children's Health identified emergency contraceptive pills as 1 of the 13 essential underused, low-cost, and high-impact commodities that could save the lives of millions of women and children worldwide. In the US, 2 emergency contraceptive regimens are currently approved, and their most plausible mechanism of action involves delaying and/or inhibiting ovulation.

AREAS OF UNCERTAINTY

Abortion and contraception are recognized as essential components of reproductive health care. In the US, in the wake of the Dobbs v. Jackson Women's Health Organization Supreme Court decision on June 24, 2022, 26 states began to or are expected to severely restrict abortion. It is anticipated that these restrictions will increase the demand for emergency contraception (EC). Several obstacles to EC access have been described, and these include cost, hurdles to over-the-counter purchase, low awareness, myths about their mechanisms of action, widespread misinformation, and barriers that special populations face in accessing them. The politicization of EC is a major factor limiting access. Improving sex education and health literacy, along with eHealth literacy, are important initiatives to improve EC uptake and access.

DATA SOURCES

PubMed, The Guttmacher Institute, Society of Family Planning, American College of Obstetrician and Gynecologists, the World Health Organization, The United Nations.

THERAPEUTIC ADVANCES

A randomized noninferiority trial showed that the 52 mg levonorgestrel intrauterine device was noninferior to the copper intrauterine device when used as an EC method in the first 5 days after unprotected intercourse. This is a promising and highly effective emergency contraceptive option, particularly for overweight and obese patients, and a contraceptive option with a different bleeding profile than the copper intrauterine device.

CONCLUSIONS

EC represents an important facet of medicine and public health. The 2 medical regimens currently approved in the US are very effective, have virtually no medical contraindications, and novel formulations are actively being investigated to make them more convenient and effective for all patient populations. Barriers to accessing EC, including the widespread presence of contraception deserts, threaten to broaden and accentuate the already existing inequities and disparities in society, at a time when they have reached the dimensions of a public health crisis.

Double Dosing Levonorgestrel-Based Emergency Contraception for Individuals With Obesity: A Randomized Controlled Trial

Increasing the dose of levonorgestrel-containing emergency contraception from 1.5 mg to 3 mg did not improve rates of ovulation delay in individuals with obesity.

OBJECTIVE:

To assess whether dose escalation (ie, doubling the dose) of emergency contraception that contains levonorgestrel (LNG) improves pharmacodynamic outcomes in individuals with obesity.

METHODS:

We enrolled healthy, reproductive-age individuals with regular menstrual cycles, body mass index (BMI) higher than 30, and weight at least 176 lbs in a randomized pharmacodynamic study. After confirming ovulation (luteal progesterone level greater than 3 ng/mL), we monitored participants with transvaginal ultrasonography and blood sampling for progesterone, luteinizing hormone, and estradiol every other day until a dominant follicle measuring 15 mm or greater was visualized. At that point, participants received either oral emergency contraception with LNG 1.5 mg or 3 mg (double dose) and returned for daily monitoring for up to 7 days. Our primary outcome was the difference in the proportion of participants with no follicle rupture 5 days postdosing (yes or no) between groups. The study had 80% power to detect a 30% difference in the proportion of cycles with at least a 5-day delay in follicle rupture (50% decrease).

RESULTS:

A total of 70 enrolled and completed study procedures. The two groups had similar baseline demographics (mean age 28 years, BMI 38). We found no difference between groups in the proportion of participants without follicle rupture more than 5 days post–LNG dosing (LNG 1.5 mg: 18/35 [51.4%]; LNG 3.0 mg: 24/35 [68.6%], P=.14). Among participants with follicle rupture before 5 days, the time to rupture did not differ between groups (day at 75% probability of no rupture is day 2 for both groups).

CONCLUSION:

Individuals with higher BMIs and weights experience a higher risk of failure of emergency contraception with LNG and exhibit an altered pharmacokinetic profile. However, the simple strategy of doubling the dose does not appear to be an effective intervention to improve outcomes.

CLINICAL TRIAL REGISTRATION:

ClinicalTrials.gov, 02859337.

[The history of emergency contraception]

Emergency contraception (EC) has evolved since the 1960's to enable a better tolerance. Lower hormone doses, simplified schemes, withdrawal of estrogens have led to a user friendly, over-the-counter available EC. The copper intra-uterine device, requiring health care professionals' intervention, is less accessible. However, it allows simultaneous initiation of a reliable long-term contraception. Unfortunately, EC is still underused and information reinforcement is needed to overcome reluctance to its use.

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.

Levonorgestrel emergency contraception and bodyweight

Objectives: Emergency contraception (EC) provides an opportunity to avoid an unwanted pregnancy following unprotected sexual intercourse (UPSI), failure of a regular contraceptive method, or after sexual assault. Two main methods are currently available: oral pills or the copper-T intrauterine device. In recent years there has been some debate regarding the efficacy of oral therapy in obese women. In this brief commentary we review new evidence, published after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) referral of 2014, relating to the effect of obesity on the pharmacokinetics and clinical efficacy of levonorgestrel EC in light of some of the concerns that have been raised. Methods: A PubMed literature search ("levonorgestrel" and "emergency contraception") was conducted between 1 January 2005 to 31 March 2018; results from the main clinical trials are discussed. Additional literature known to the authors and identified from the reference lists of cited publications was included. Results: Overall, it should be noted that, in studies which determined pregnancy rates across different weight or BMI categories, the overall pregnancy rate was low (1-2%) and there was no direct evidence that lower levonorgestrel plasma levels contributed to an increased pregnancy rate in obese women. This conclusion was reached by the EMA referral in 2014 and they concluded that emergency contraceptive pills (ECPs) could be taken regardless of body weight or BMI, as soon as possible after UPSI. Since the EMA review, additional evidence has been published regarding this topic. This includes PK data (which can neither support, nor deny the previously submitted meta-analyses during the Article 31 Referral procedure), or re-analyses of the previously submitted data. Conclusions: Evidence published since the EMA referral in 2014 does not change the original conclusions of the agency, which recommended that ECPs could be taken regardless of body weight or BMI, as soon as possible after UPSI.

Systematic Review of Ovarian Activity and Potential for Embryo Formation and Loss during the Use of Hormonal Contraception

The purpose of this review was to determine whether there is evidence that ovulation can occur in women using hormonal contraceptives and whether these drugs might inhibit implantation. We performed a systematic review of the published English-language literature from 1990 to the present which included studies on the hormonal milieu following egg release in women using any hormonal contraceptive method. High circulating estrogens and progestins in the follicular phase appear to induce dysfunctional ovulation, where follicular rupture occurs but is followed by low or absent corpus luteum production of progesterone. Hoogland scoring of ovulatory activity may inadvertently obscure the reality of ovum release by limiting the term "ovulation" to those instances where follicular rupture is followed by production of a threshold level of luteal progesterone, sufficient to sustain fertilization, implantation, and the end point of a positive β-human chorionic gonadotropin. However, follicular ruptures and egg release with subsequent low progesterone output have been documented in women using hormonal contraception. In the absence of specific ovulation and fertilization markers, follicular rupture should be considered the best marker for egg release and potential fertilization. Women using hormonal contraceptives may produce more eggs than previously described by established criteria; moreover, suboptimal luteal progesterone production may be more likely than previously acknowledged, which may contribute to embryo loss. This information should be included in informed consent for women who are considering the use of hormonal contraception.

Summary

For this study, the authors looked at English-language research articles that focused on how hormonal birth control, such as the birth control pill, may affect very early human embryos. The authors found that abnormal ovulation, or release of an egg followed by abnormal hormone levels, may often occur in women using hormonal birth control. This may increase the number of very early human embryos who are lost before a pregnancy test becomes positive. For women who are thinking about using hormonal birth control, this is important information to consider.

[Emergency contraception: CNGOF Contraception Guidelines]

OBJECTIVES

Edit, by the French National College of Gynecologists and Obstetricians (CNGOF), recommendations based on the evidence available in the literature for the use in terms of effectiveness, safety and side effects of emergency contraception (EC).

METHODS

A review of the literature was conducted by consulting Medline, Cochrane Library and international recommendations in French and English from January 1, 1979 to May 1, 2018.

RESULTS

It is recommended to inform patients that EC is not 100% effective. A pregnancy test is recommended if there is a delay after taking an EC. It is recommended to use EC as soon as possible after the unprotected intercourse. In the absence of long-term contraception, in the first 72hours after unprotected intercourse, ulipristal acetate (UPA) and levonorgestrel (LNG) may be offered with a superiority of UPA from 0 to 72h. Beyond 72hours, the data suggest a better efficiency of the UPA. However, taking into account practical elements (access to EC, cost, impact on the taking of hormonal contraception after UPA), it is difficult to recommend the UPA as a priority between 0 and 72h. Menstruation is more likely to happen early with LNG. The copper IUD is an effective method that can be used in EC until 120hours after unprotected intercourse or when there is a risk of contraceptive failure.

CONCLUSIONS

EC is not 100% effective. The closer the intake of EC with the unprotected intercourse, the more effective is the EC in terms of pregnancy rate.

Model for Hormonal Emergency Contraception (HEC) in cycling and mated guinea pigs - Studies with the Progesterone Receptor Modulators (PRM) Ulipristal Acetate (UPA/CDB2914) and EC317

A guinea pig model for new HEC methods is proposed. Two targets for HEC (Hormonal Emergency Contraception), ovulation and conception (post-mating study), were investigated using adjusted PRM treatments: (a) Ovulation inhibition study: Injections on cycle days 10-17, study of ovarian histology on day 18; (b) post-mating study: Injections on cycle days 1 and 2; rate of pregnant females was recorded at autopsy on day 18. P plasma levels permitted assessment of effects on ovulation in non-conceiving animals.

RESULTS

(a) All controls had recently ovulated. Statistically significant anti-ovulatory effects (p < 0.05, Fisher's Exact Test) were seen at 10 mg UPA (ulipristal acetate, CDB2914) and ≥0.3 mg EC317; 100% inhibition was found for EC317 at 10, 3, and 1 mg/day. No dosage of UPA was 100% effective. (b) In post-mating studies, 16 of 30 controls were pregnant. Both PRMs (progesterone receptor modulator) exerted inhibitory effects on conception, none on imminent ovulation; 1 of 10 animals had living conceptuses after 10 mg UPA, none following 10 and 1 mg EC317/day, respectively. At pairwise comparison with controls, 10 mg was the lowest effective dosage for UPA (p < 0.05), and 1 mg for EC317 (p < 0.01). P plasma levels: Significantly lower P (p < 0.05) in subsequently pregnant vs non-pregnant controls was found on cycle day 3 or 4; this difference disappeared on day 8 or 9. This stage thus appears vulnerable to hormonal constellations and possibly PRM effects. HEC model: Effects on ovulation and conception were seen at the same dose levels of both PRM. Superior and more consistent effects of EC317 vs UPA (factor ≥10) suggest higher efficacy using EC317 for HEC.

Emergency contraceptive knowledge, attitudes and practices among female students at the University of Botswana: A descriptive survey

Background

Unintended pregnancies are associated with unsafe abortions and maternal deaths, particularly in countries such as Botswana, where abortion is illegal. Many of these unwanted pregnancies could be avoided by using emergency contraception, which is widely available in Botswana.

Aim

To assess the level of knowledge, attitudes and practices of female students with regard to emergency contraception at the University of Botswana.

Setting

Students from University of Botswana, Gaborone, Botswana.

Methods

A descriptive survey among 371 students selected from all eight faculties at the university. Data were collected using a self-administered questionnaire and analysed using the Statistical Package for Social Sciences.

Results

The mean age was 20.6 years (SD 1.62), 58% were sexually active, 22% had used emergency contraception and 52% of pregnancies were unintended. Of the total respondents, 95% replied that they had heard of emergency contraception; however, only 53% were considered to have good knowledge, and 55% had negative attitudes towards its use. Students from urban areas had better knowledge than their rural counterparts (p = 0.020). Better knowledge of emergency contraception was associated with more positive attitudes towards actual use (p < 0.001). Older students (p < 0.001) and those in higher years of study (p = 0.001) were more likely to have used emergency contraception.

Conclusion

Although awareness of emergency contraception was high, level of knowledge and intention to use were low. There is a need for a targeted health education programme to provide accurate information about emergency contraception.

State of emergency contraception in the U.S., 2018

Emergency contraception is indicated in instances of unprotected sexual intercourse, including reproductive coercion, sexual assault, and contraceptive failure. It plays a role in averting unintended pregnancies due to inconsistent use or non-use of contraception. Options for emergency contraception vary by efficacy as well as accessibility within the U.S. This paper provides an overview of levonorgestrel (Plan B One-Step and generic counterparts), ulipristal acetate (sold as ella), and the copper intrauterine device (IUD, sold as ParaGard), including the mechanisms of action, administration, efficacy, drug interactions, safety, side effects, advantages, and drawbacks. It will also review current misconceptions about emergency contraception and access for subpopulations, including adolescents, immigrants, survivors of sexual assault, rural populations, and military/veteran women. This paper will address barriers such as gaps in knowledge, and financial, health systems, and practice barriers. Continuing areas of research, including the impact of body weight on the efficacy of emergency contraceptive pills and potential interactions between ulipristal acetate and ongoing hormonal contraceptives, are also addressed.

Uterine flushings from women treated with levonorgestrel affect sperm functionality in vitro

Levonorgestrel (LNG), a synthetic 19 nor-testosterone derivative, is widely used for emergency contraception. It is well known that LNG prevents ovulation only when given prior to the surge of serum luteinizing hormone (LH) during the periovulatory phase of the menstrual cycle. This observation suggests that LNG, given its contraceptive efficacy, has additional effects other than those affecting ovulation. In this study, we have evaluated the effects on human sperm functionality of uterine flushings (UF) obtained from women at day LH + 1 of a control cycle (CTR-LH + 1) and after receiving LNG (LNG-LH + 1) two days before the surge of LH. Human sperm from normozoospermic donors were incubated with UF and protein tyrosine phosphorylation, sperm motility, acrosome reaction as well as zona pellucida (ZP) binding capacity were assessed. A significant decrease in total motility and tyrosine phosphorylation accompanied by an increase on spontaneous acrosome reaction was observed when sperm were incubated in the presence of LNG-LH + 1. None of these effects were mimicked by purified glycodelin A (GdA). Moreover, the addition of UF obtained during the periovulatory phase from LNG-treated women or the presence of purified GdA significantly decreased sperm-ZP binding. The data were compatible with changes affecting sperm capacitation, motility and interaction with the ZP. These results may offer evidence on additional mechanisms of action of LNG as an emergency contraceptive.

Ulipristal acetate administration at mid-cycle changes gene expression profiling of endometrial biopsies taken during the receptive period of the human menstrual cycle

The aim of this study was to analyze the effects of mid-cycle administration of Ulipristal acetate (UPA) on gene expression in endometrial biopsies taken during the receptive phase of the cycle. Fourteen healthy menstruating women were studied during 14 control non-treated and 12 treated cycles with a single dose of 30 mg UPA when follicle diameter reached 20 mm. Ovulation in both treated and control cycles was confirmed by serial determinations of serum LH, progesterone and vaginal ultrasound. An endometrial biopsy at day LH+7, in each cycle, was taken for RNA microarray and qPCR analysis or prepared for histological and immunohistochemistry studies. Functional analysis of differentially expressed genes showed the presence of changes compatible with a non-receptive endometrial phenotype, further confirmed by qPCR and immunohistochemistry. This study suggests the effects of UPA on endometrial receptivity, offering a plausible explanation for the higher contraceptive efficacy of this method compared to that of levonorgestrel.

Experience with oral emergency contraception since the OTC switch in Germany

PURPOSE

In March 2015, the oral emergency contraceptives levonorgestrel (LNG) and ulipristal acetate (UPA) were released from prescription-only status in Germany. The main research question is to analyse whether the OTC status of oral emergency contraceptives has an influence on the patterns of use.

METHODS

All information is based on searches for public domain sources on emergency contraception. Searches were made for scientific publications, statistics, and surveys.

RESULTS

Due to additional active ingredient properties, UPA is superior to LNG in terms of ovulation-inhibiting effect. Since the OTC switch, demand for oral emergency contraceptives has risen by almost 50%, especially at weekends when sexual encounters and thus contraceptive failures are most frequent. However, the age distribution of the users has not changed as a result of the OTC switch. Doctors still play an important role in advising on emergency contraception after the removal of the prescription-only requirement. Pregnancies despite emergency contraception are terminated in more than half of the cases. In federal states with higher rates of use of the morning-after pill, fewer terminations of pregnancy were performed.

CONCLUSION

As a result of the OTC switch, more women and girls use the morning-after pill after unprotected intercourse and the time between unprotected intercourse and taking the oral emergency contraceptive decreases. This is of great advantage in terms of the mechanism of action. UPA is used more frequently than LNG. Only half of all people aged between 16 and 39 years in Germany are aware of the morning-after pill and 94% of women who had a pregnancy terminated in 2015 did not use any emergency contraception after the unprotected intercourse. In the population, there is still a great need for information and education on contraception and emergency contraception.

Effects of a single 20 mg dose of letrozole on ovarian function post dominant follicle selection: an exploratory randomized controlled trial

BACKGROUND

Our objective was to explore the impact of a single dose of an aromatase inhibitor (letrozole) administered at defined times of the follicular phase or immediately after ovulation on dominant follicle development, luteogenesis and new follicle wave emergence.

METHODS

A prospective pilot study using a randomized complete block, controlled, open label design was conducted at an academic clinical research center. Forty-five healthy, female volunteers (25.5 ± 0.9 years, BMI 25.0 ± 0.6 kg/m2) who had not taken hormonal contraceptives for a minimum of 2 months were recruited. A 20 mg dose of Letrozole was administered once orally in each of 3 groups when the dominant follicle reached a diameter of 1) 12 mm, 2) 18 mm, 3) the first day following ovulation (post-ovulation), or 4) treatment was withheld (control). Serial ultrasonography and phlebotomy began on day 4 of the menstrual cycle and continued for 1.5 menstrual cycles. Participants recorded menses and daily events in a life events calendar for the duration of the study. Demographic and single point measurements were compared among groups by ANOVA. Changes in hormone concentrations over time were compared among groups by repeated measures ANOVA. Kruskal-Wallis tests were used for non-normally distributed data.

RESULTS

The dominant follicle in all treatment groups ovulated. There were no differences among experimental groups in peak follicle diameter, follicular growth rate, endometrial thickness at ovulation or inter-ovulatory interval. Plasma concentrations of estradiol dropped, while FSH and LH concentrations rose following treatment in all treatment groups. Plasma FSH and LH concentrations were higher in the 18 mm group compared to the 12 mm and post-ovulation groups (P < 0.02).

CONCLUSION

Administration of a single 20 mg dose of Letrozole at the times of the menstrual cycle we examined did not induce dominant follicle regression or failure of corpus luteum formation. Letrozole-induced suppression of estradiol synthesis by the dominant follicle was not detrimental to follicle growth or ovulation following follicle selection, likely due to increased circulating concentrations of FSH and LH resulting from a lack of estradiol-induced suppression of the hypothalamic-pituitary-ovarian axis.

TRIALS REGISTRATION NUMBER

Clinical trials registration number NCT01046578 .

Repeated use of mifepristone and levonorgestrel and their effect on the ovarian function in mice

AIM

To investigate the effects of repeated mifepristone and levonorgestrel use on estrous cycle and expression of ovarian follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in mice.

METHODS

Ovarian FSHR and LHR mRNA expression was measured using real-time quantitative reverse transcription-polymerase chain reaction, while the protein levels were measured using immunohistochemistry.

RESULTS

Repeated use of mifepristone and levonorgestrel significantly lengthened the estrous cycle and decreased FSHR and LHR mRNA and protein expression in the ovaries of mice at 4, 24, and 48 days after discontinuing drug use. Repeated use of mifepristone and levonorgestrel had significant main effects on estrous cycle length and the mRNA expression and protein level of ovarian FSHR and LHR. Repeated mifepristone and levonorgestrel use and withdrawal time had a significant interaction with mouse estrous cycle (F = 16.65, P < 0.05), ovarian LHR and FSHR mRNA expression (F = 563.072, P < 0.05), and protein level (F = 6.536, P < 0.05).

CONCLUSION

Repeated use of mifepristone and levonorgestrel can lead to sustained damage to ovarian function through inhibition of ovarian FSHR and LHR expression in mice.

Effect of single post-ovulatory administration of mifepristone (RU486) on transcript profile during the receptive period in human endometrium

Progesterone regulates uterine function during the luteal phase and is essential for the acquisition of endometrial receptivity. The objective of the present study was to identify endometrial transcripts whose expression is altered during the window of implantation after the administration of 200 mg of the antiprogestin mifepristone, 48 h after the LH peak (LH+2, LH+0=LH peak), and to determine the relationship of these transcripts with those regulated during the acquisition of receptivity. Endometrial samples were obtained in LH+7 from seven women of proven fertility, each one contributing with one cycle treated with placebo and another with mifepristone. Additionally, endometrial samples were obtained in LH+2 and LH+7 during a single untreated spontaneous cycle from seven normal fertile women as a reference. DNA microarrays were used to identify transcripts significantly regulated (defined as ≥2.0-fold change with false discovery rate below 1% usingt-test) with the administration of mifepristone vs placebo, or during the transition from pre-receptive to receptive (LH+2 vs LH+7). Approximately 2000 transcripts were significantly regulated in both comparisons (mifepristone vs placebo and LH+2 vs LH+7), but only 777 of them were coincident and displayed opposite regulation except for 25. The mRNA level for eight selected genes regulated by mifepristone was confirmed by real-time RT-PCR. We conclude that not all changes in endometrial transcript levels occurring in the transition from LH+2 to LH+7 seem to be regulated by the progesterone receptor and ∼37% of the genes whose transcript levels changed by effect of mifepristone could be associated with the acquisition of receptivity.

A prospective, open-label, single arm, multicentre study to evaluate efficacy, safety and acceptability of pericoital oral contraception using levonorgestrel 1.5 mg

STUDY QUESTION

Will the use of levonorgestrel (LNG) 1.5 mg taken at each day of coitus by women who have relatively infrequent sex be an efficacious, safe and acceptable contraceptive method?

SUMMARY ANSWER

Typical use of LNG 1.5 mg taken pericoitally, before or within 24 h of sexual intercourse, provides contraceptive efficacy of up to 11.0 pregnancies per 100 women-years (W-Y) in the primary evaluable population and 7.1 pregnancies per 100 W-Y in the evaluable population.

WHAT IS KNOWN ALREADY

LNG 1.5 mg is an effective emergency contraception following unprotected intercourse. Some users take it repeatedly, as their means of regular contraception.

STUDY DESIGN, SIZE, DURATION

This was a prospective, open-label, single-arm, multicentre Phase III trial study with women who have infrequent coitus (on up to 6 days a month). Each woman had a follow-up visit at 2.5, 4.5 and 6.5 months after admission or until pregnancy occurs if sooner, or she decided to interrupt participation. The study was conducted between 10 January 2012 and 15 November 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 330 healthy fertile women aged 18-45 years at risk of pregnancy who reported sexual intercourse on up to 6 days a month, were recruited from four university centres located in Bangkok, Thailand; Campinas, Brazil; Singapore and Szeged, Hungary to use LNG 1.5 mg pericoitally (24 h before or after coitus) as their primary method of contraception. The participants were instructed to take one tablet every day she had sex, without taking more than one tablet in any 24-h period, and to maintain a paper diary for recording date and time for every coital act and ingestion of the study tablet, use of other contraceptive methods and vaginal bleeding patterns. Anaemia was assessed by haemoglobin evaluation. Pregnancy tests were performed monthly and pregnancies occurring during product use were assessed by ultrasound. At the 2.5-month and final visit at 6.5 months, acceptability questions were administered.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 321 women included in the evaluable population (which includes all eligible women enrolled), with 141.9 woman-years (W-Y) of observation and with a rate (95% confidence interval [CI]) of 7.1 (3.8; 13.1) pregnancies per 100 W-Y of typical use (which reflects use of the study drug as main contraceptive method, but also includes possible use of other contraceptives from admission to end of study) and 7.5 (4.0; 13.9) pregnancies per 100 W-Y of sole use. In the primary evaluable population (which includes only eligible enrolled women <35 years old), the rate was 10.3 (5.4; 19.9) pregnancies per 100 W-Y of typical use, and 11.0 (5.7; 13.1) pregnancies per 100 W-Y of sole use. There were three reported severe adverse events and 102 other mild adverse events (most common were headache, nausea, abdominal and pelvic pain), with high recovery rate. The vaginal bleeding patterns showed a slight decrease in volume of bleeding and the number of bleeding-free days increased over time. There was only one case of severe anaemia, found at the final visit (0.4%). The method was considered acceptable, as over 90% of participants would choose to use it in the future or would recommend it to others.

LIMITATIONS, REASONS FOR CAUTION

This was a single-arm study with small sample size, without a control group, designed as a proof of concept study to explore the feasibility of this type of contraception.

WIDER IMPLICATIONS OF THE FINDINGS

A larger clinical study evaluating pericoital contraception with LNG is feasible and our data show that this method would be acceptable to many women.

STUDY FUNDING/COMPETING INTERESTS

This study received partial financial support from the UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research (RHR) and the World Health Organization. Gynuity and the Bill and Melinda Gates Foundation (BMGF) provided financial support for project monitoring. HRA Pharma donated the LNG product. N.K. was the initial project manager when she was with WHO/HRP and was employed by HRA Pharma, which distributes LNG for emergency contraception. The other authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

This study was registered on ANZCTR, Trial ID ACTRN12611001037998.

TRIAL REGISTRATION DATE

4 October 2011.

DATE OF FIRST PATIENT'S ENROLMENT

10 January 2012.

Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action

BACKGROUND

Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function.

OBJECTIVE

The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects.

CONCLUSION

The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect.

LAY SUMMARY

Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug's mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA.

Appreciation for Analysis of how Levonorgestrel Works and Reservations with the use of Meloxicam as Emergency Contraception

This paper is a response to Dr. Kathleen Raviele's recent article on her critical analysis of the use of levonorgestrel given to women postsexual assault and her suggestion that the use of Meloxicam may be an ethical alternative.

Mechanism of Action of Ulipristal Acetate for Emergency Contraception: A Systematic Review

Ulipristal acetate (UPA) is now recommended as first choice hormonal emergency contraception (EC), due to its higher efficacy and similar safety compared to Levonorgestrel - EC. Even though all trials demonstrated that the first mechanism of action is inhibition of ovulation, some authors still postulate that a post fertilization effect is also possible, raising the alert on medication and fostering the ethical debate. A Medline database search was performed in order to find recent articles related to UPA's effects on ovulation, on fallopian tube and on endometrium. We also analyzed the effects on sperm function and pregnancy. All studies conclude that UPA is effective in inhibition of ovulation even when administered shortly before LH peak. The effects on fallopian tube are unclear: according to some authors UPA inhibits ciliar beat through an agonistic effect on progesterone receptors, according to others it antagonizes the progesterone-induced ciliar beat decrease. Concerning the action on endometrium and on embryo implantation most of the studies concluded that low dose UPA used for EC has no significant effect on the decrease of endometrial thickness and on embryo's attachment, but these results are still matter of debate. Finally recent evidence suggests that UPA modulates human sperm functions while it has no effect on established pregnancy. To date the majority of the evidence concurs in excluding a post-fertilization effect of UPA, even though more studies are needed to clarify its mechanism of action.

Impact of bodyweight/body mass index on the effectiveness of emergency contraception with levonorgestrel: a pooled-analysis of three randomized controlled trials

OBJECTIVE

A pooled analysis of two randomized controlled trials (RCTs) suggested that increased bodyweight and body mass index (BMI) may be associated with a greater probability of pregnancy. To address this issue we investigated whether higher bodyweight and/or BMI negatively impacted the risk of pregnancy in women receiving LNG-EC (levonorgestrel - emergency contraception) after unprotected sexual intercourse in a pooled analysis of three large multinational RCTs conducted by the World Health Organization (WHO).

METHODS

A pooled analysis of three double-blind, multinational RCTs conducted by the WHO to investigate the efficacy of LNG-EC in the general population. All analyses were done on the per-protocol set (PPS) which included 5812 women who received LNG-EC within 72 hours following unprotected sexual intercourse. The analysis was based on logistic regression, with pregnancy as the outcome. BMI and weight were represented in the same model.

RESULTS

A total of 56 pregnancies were available for analysis in the PPS. Increasing bodyweight and BMI were not correlated with an increased risk of pregnancy in the studied population. A limitation of this study is that despite the large study population in the pooled analysis there were relatively small numbers of women in the high-BMI and high-bodyweight subgroups.

CONCLUSION

LNG-EC is effective for preventing pregnancy after unprotected intercourse or contraceptive failure and no evidence was found to support the hypothesis of a loss of EC efficacy in subjects with high BMI or bodyweight. Therefore, access to LNG-EC should not be limited only to women of lower bodyweight or BMI.

Pharmacokinetic and pharmacodynamic drug interactions between antiretrovirals and oral contraceptives

More than 50 % of women living with HIV in low- and middle-income countries are of reproductive age, but there are limitations to the administration of oral contraception for HIV-infected women receiving antiretroviral therapy due to drug-drug interactions caused by metabolism via the cytochrome P450 isoenzymes and glucuronidation. However, with the development of newer antiretrovirals that use alternative metabolic pathways, options for contraception in HIV-positive women are increasing. This paper aims to review the literature on the pharmacokinetics and pharmacodynamics of oral hormonal contraceptives when given with antiretroviral agents, including those currently used in developed countries, older ones that might still be used in salvage regimens, or those used in resource-limited settings, as well as newer drugs. Nucleos(t)ide reverse transcriptase inhibitors (NRTIs), the usual backbone to most combined antiretroviral treatments (cARTs) are characterised by a low potential for drug-drug interactions with oral contraceptives. On the other hand non-NRTIs (NNRTIs) and protease inhibitors (PIs) may interact with oral contraceptives. Of the NNRTIs, efavirenz and nevirapine have been demonstrated to cause drug-drug interactions; however, etravirine and rilpivirine appear safe to use without dose adjustment. PIs boosted with ritonavir are not recommended to be used with oral contraceptives, with the exception of boosted atazanavir which should be used with doses of at least 35 µg of estrogen. Maraviroc, an entry inhibitor, is safe for co-administration with oral contraceptives, as are the integrase inhibitors (INIs) raltegravir and dolutegravir. However, the INI elvitegravir, which is given in combination with cobicistat, requires a dose of estrogen of at least 30 µg. Despite the growing evidence in this field, data are still lacking in terms of large cohort studies, randomised trials and correlations to real clinical outcomes, such as pregnancy rates, in women on antiretrovirals and hormonal contraception.

Responses to various exposure durations of levonorgestrel during early-life stages of fathead minnows (Pimephales promelas)

Pharmaceuticals are routinely detected in the environment; and several of these compounds have been extensively researched due to their potential impacts to the endocrine system of aquatic organisms. The negative reproductive consequences of synthetic progestins in teleost species have only recently been investigated. The current study examined different exposure periods that may be most sensitive for levonorgestrel (LNG) in early-life stages of fathead minnow larvae. Larvae were exposed to a single concentration of LNG (125ng/L) for different durations from fertilized egg through 28 days post hatch (dph) with growth and mRNA expression of FSH, 3β-HSD, 20β-HSD, and CYP19a1 measured. Regardless of the duration of exposure, LNG significantly decreased growth in the fathead minnow larvae at day 28. For both 20β-HSD and CYP19a1, mRNA expression was decreased following LNG exposure durations ≥7 days. 3β-HSD and FSH showed similar trends after exposure to LNG with later stages of development exhibiting decreased expression. 20β-HSD and 3β-HSD were the only transcripts to remain down regulated once larvae were moved to clean water after the 7-14dph LNG exposure. This study is the first to investigate the effects of exposure time to a synthetic progestin on developing fish. Future research is needed to understand what impacts these changes have on adult stages of development.

Reduced prevalence of chronic tubal inflammation in tubal pregnancies after levonorgestrel emergency contraception failure

PURPOSE

The aim of this study was to compare chronic fallopian tubal inflammatory disease and fibrosis between patients with general tubal pregnancy (TP) and TP with levonorgestrel (LNG) emergency contraception (EC) failure.

METHODS

We retrospectively studied patients with general TP (n = 79) and TP following LNG-EC failure (n = 81) within the same conception cycle. Information on the gynecological features of each subject was collected. Pelvic inflammatory disease and associated sequelae were assessed by the serum Chlamydia trachomatis (CT) IgG test, laparoscopic evaluation of tubal damage, and histopathological observation of tube tissues. Chi-square and Student's t-tests were employed to determine the difference between the two groups.

RESULTS

Compared with general TP, cases of TP following LNG-EC failure subjects were less likely to have a history of previous ectopic pregnancy (5.06% vs. 18.52%, p = 0.009) and adnexal surgery (6.33% vs. 22.22%, p = 0.010). Patients with TP following LNG-EC failure were less likely to have pelvic inflammatory disease and associated sequelae than those with general TP, as revealed by positive reaction to anti-CT IgG (18.18% vs. 35.94%, p = 0.031), assessment of tubal damage (grade I: 5.06% vs. 17.28%; grade II: 2.53% vs. 11.11%; grade III: 1.27% vs. 6.17%; p = 0.001), infiltration of chronic inflammatory cells (10.91% vs. 62.50%, p < 0.001), and positive Masson's staining (7.69% vs. 39.58%; p < 0.001).

CONCLUSIONS

Compared with cases of general TP, cases of TP following LNG-EC failure exhibited reduced rates of CT infection, fallopian tubal inflammation, and/or fibrosis.

Effects of ulipristal acetate on human embryo attachment and endometrial cell gene expression in an in vitro co-culture system

STUDY QUESTION

Does ulipristal acetate (UPA) used for emergency contraception (EC) interfere with the human embryo implantation process?

SUMMARY ANSWER

UPA, at the dosage used for EC, does not affect human embryo implantation process, in vitro.

WHAT IS KNOWN ALREADY

A single pre-ovulatory dose of UPA (30 mg) acts by delaying or inhibiting ovulation and is recommended as first choice among emergency contraceptive pills due to its efficacy. The compound has also been demonstrated to have a dose-dependent effect on the endometrium, which theoretically could impair endometrial receptivity but its direct action on human embryo implantation has not yet been studied.

STUDY DESIGN, SIZE, DURATION

Effect of UPA on embryo implantation process was studied in an in vitro endometrial construct. Human embryos were randomly added to the cultures and cultured for 5 more days with UPA (n = 10) or with vehicle alone (n = 10) to record the attachment of embryos.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Endometrial biopsies were obtained from healthy, fertile women on cycle day LH+4 and stromal and epithelial cells were isolated. A three-dimensional in vitro endometrial co-culture system was constructed by mixing stromal cells with collagen covered with a layer of epithelial cells and cultured in progesterone containing medium until confluence. The treatment group received 200 ng/ml of UPA. Healthy, viable human embryos were placed on both control and treatment cultures. Five days later the cultures were tested for the attachment of embryos and the 3D endometrial constructs were analysed for endometrial receptivity markers by real-time PCR.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant difference in the embryo attachment rate between the UPA treated group and the control group as 5 out of 10 human embryos exposed to UPA and 7 out of 10 embryos in the control group attached to the endometrial cell surface (P = 0.650). Out of 17 known receptivity genes studied here, only 2 genes, HBEGF (P = 0.009) and IL6 (P = 0.025) had a significant up-regulation and 4 genes, namely HAND2 (P = 0.003), OPN (P = 0.003), CALCR (P = 0.016) and FGF2 (P = 0.023) were down-regulated with the exposure of UPA, compared with control group.

LIMITATIONS, REASONS FOR CAUTION

This proof of concept study was conducted with a few human embryos, as their availability was limited. Although the 3D model used for this study is well established and the artificial endometrial luminal epithelium shown to express progesterone regulated markers of endometrial receptivity it is still an in vitro model, lacking all cell types that constitute the receptive endometrium in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides new insights on the mechanism of action of UPA on human embryo implantation, demonstrating that UPA in a dosage used for EC does not affect embryo viability and the implantation process of embryo. Progesterone receptor modulators (PRMs) hold the potential to be attractive estrogen- and gestagen-free contraceptives and thus may be made available to a larger proportion of women globally due to these findings.

STUDY FUNDING/COMPETING INTERESTS

Swedish Research Council (K2010-54X-14212-09-3) and support provided through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska University Hospital.

Mechanism of action of levonorgestrel emergency contraception

There has been much debate regarding levonorgestrel emergency contraception's (LNG-EC's) method of action since 1999 when the Food and Drug Administration first approved its use. Proponents of LNG-EC have argued that they have moral certitude that LNG-EC works via a non-abortifacient mechanism of action, and claim that all the major scientific and medical data consistently support this hypothesis. However, newer medical data serve to undermine the consistency of the non-abortifacient hypothesis and instead support the hypothesis that preovulatory administration of LNG-EC has significant potential to work via abortion. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room protocols. In the future, technology such as the use of early pregnancy factor may have the potential to quantify how frequently preovulatory LNG-EC works via abortion. Lay Summary: How Plan B (levonorgestrel emergency contraception) works has been vigorously debated ever since the Food and Drug Administration approved it in 1999. Many doctors and researchers claim that it has either no-or at most-an extremely small chance of working via abortion. However, the latest scientific and medical evidence now demonstrates that levonorgestrel emergency contraception theoretically works via abortion quite often. The implications of the newer data have important ramifications for medical personnel, patients, and both Catholic and non-Catholic emergency room rape protocols.

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

OBJECTIVE

In 2001, we provided benchmark estimates of probability of pregnancy given a single act of intercourse. Those calculations assumed that intercourse and ovulation are independent. Subsequent research has shown that this assumption is not valid. We provide here an update of previous benchmark estimates.

STUDY DESIGN

We reanalyze earlier data from two North Carolina studies that collected daily urine samples and recorded daily intercourse for multiple menstrual cycles. One study comprised 68 sexually active women with either an intrauterine device or tubal ligation. The second was of 221 women who planned to become pregnant and had discontinued use of any birth control at enrollment. Participants had no known fertility problems. New statistical analyses were based on Monte Carlo simulations and Bayesian methods.

RESULTS

The probability that a single act of intercourse occurs within a woman's fertile window is 25%, compared with 20% in previous calculations. The probability of pregnancy with intercourse on a given menstrual cycle day is correspondingly higher than previously estimated, with the largest increases occurring on menstrual days 12-22. These increases are, however, fairly small (for example, the peak chance of conception on menstrual day 13 increased from 8.6% to 9.7%).

CONCLUSIONS

Previous benchmark rates of pregnancy with one act of intercourse were moderately underestimated due to a mistaken assumption about the independence of intercourse and ovulation.

IMPLICATIONS STATEMENT

The chance of pregnancy with a single act of unprotected intercourse is greater than previously estimated. Previous benchmarks may underestimate the efficacy of post-coital contraception.

Risk factors and clinical features of ovarian pregnancy: a case-control study

OBJECTIVE

To identify risk factors for ovarian pregnancy (OP) and compare clinical features between OP and tubal pregnancy (TP) patients.

DESIGN

Case-control study.

SETTING

University hospital.

PARTICIPANTS

A case-control study was conducted from January 2005 to May 2014. Women diagnosed with OP were recruited as the case group (n=71), 145 women with TP and 146 with intrauterine pregnancy (IUP) were matched as controls at a ratio of 1:2:2. Women who refused interviews or provided incomplete information were excluded.

RESULTS

OP risk was lower than TP risk in women with serological evidence of Chlamydia trachomatis infection (adjusted OR1 0.17, 95% CI 0.06 to 0.52), previous adnexal surgery (adjusted OR1 0.25, 95% CI 0.07 to 0.95), and current levonorgestrel emergency contraceptive use (adjusted OR1 0.24, 95% CI 0.07 to 0.78). In vitro fertilisation-embryo transfer (IVF-ET) carried a higher risk of OP (adjusted OR1 12.18, 95% CI 2.23 to 66.58) than natural conception. When Controlled by IUP women, current users of intrauterine devices (IUDs) carried a higher risk of OP than non-users of any contraceptives (adjusted OR2 9.60, 95% CI 1.76 to 42.20). β-Human chorionic gonadotropin (hCG) levels on the day of surgery were higher in OP patients than in TP patients (p<0.01). Women with OP were less likely to initially present with vaginal bleeding than those with TP (p=0.02). Moreover, shock (p=0.02), rupture (p<0.01), haemoperitoneum (p<0.01) and emergency laparotomy (p<0.01) were more common in the OP group than in the TP group.

CONCLUSIONS

IVF-ET and IUD use may be risk factors for OP, and OP patients tend to have high β-hCG levels and a poor clinical outcome (shock, rupture, haemoperitoneum and need for emergency laparotomy). Our findings may contribute to the prevention and early diagnosis of OP.

Recent advances in contraception

Focusing on intrauterine contraceptives (IUC), contraceptive implants, and emergency contraceptives, we review recent advances in contraceptive development and discuss progress in policies to improve access to the most effective methods. We report on the shift in practice towards routinely providing IUCs and implants to young and nulliparous women, prompted in part by the reduced diameter of the insertion tube for the Mirena IUC and the development of a smaller IUC called Skyla. Additionally, we describe the new SCu300A intrauterine ball and the development of an implant called Nexplanon, which comes with a preloaded inserter. We also discuss the efficacy of ulipristal acetate versus levonorgestrel for emergency contraception, especially for women who weigh more than 75 kg. Finally, in light of the increasing interest in providing IUCs and implants to women in the immediate postpartum and post-abortion periods, we consider the rationale for this change in practice and review the progress that has been made so far in the United States.

Effect of body weight and BMI on the efficacy of levonorgestrel emergency contraception

OBJECTIVES

To further evaluate the effect of weight and body mass index (BMI) on the efficacy of levonorgestrel emergency contraception.

METHODS

Data from two large, multicenter, randomized controlled trials designed to assess emergency contraceptive efficacy were pooled to evaluate the effect of weight and BMI on pregnancy rates among women who received levonorgestrel. Descriptive methods (comparison of means and distributions according to pregnancy status and pregnancy rates across weight and BMI categories) as well as cubic spline modeling were used to describe the relationship between pregnancy risk and weight/BMI.

RESULTS

The analysis population comprised 1731 women, among whom 38 pregnancies were reported. Women for whom levonorgestrel was not effective in preventing pregnancy had a significantly higher mean body weight and BMI than women who did not become pregnant (76.7 vs. 66.4 kg, p<.0001; 28.1 vs. 24.6 kg/m², p<.0001). The estimated pregnancy rate increased significantly from 1.4% [95% confidence interval (CI): 0.5%-3.0%] among the group of women weighing 65-75 kg to 6.4% (95% CI: 3.1%-11.5%) and 5.7% (95% CI: 2.9%-10.0%) in the 75-85 kg and >85 kg groups, respectively. Statistical modeling demonstrated a steep increase in pregnancy risk starting from a weight near 70-75 kg to reach a risk of pregnancy of 6% or greater around 80 kg. Similar results were obtained for statistical modeling of BMI as well as when the two studies were analyzed individually.

CONCLUSIONS

All analyses showed a significant drop in the efficacy of levonorgestrel emergency contraception with increasing body weight, with pregnancy risk in the higher weight categories similar to expected rates in the absence of contraception. Like body weight, increasing BMI was highly correlated with increased pregnancy risk.

Contraception and sexual health in obese women

As the proportion of women with obesity increases worldwide, understanding the influence of body weight on sexual behavior, fertility, and contraceptive effectiveness is critical for health-care professionals and patients. Although many have theorized that obese women are different from normal-weight women regarding sexual health and behavior, current evidence for the most part disproves this. The exception is in adolescents where body image may play a role in riskier behavior, placing them at a greater risk of an unintended pregnancy. Given that most modern contraceptives were not originally evaluated in obese women, understanding how weight affects contraceptive pharmacokinetics and efficacy should be a focus of ongoing research. Evidence is reassuring that most modern contraceptive methods are safe and effective in obese women. This paper reviews what is known about sexual and contraceptive behavior, as well as the effectiveness and pharmacokinetics of modern contraceptives, for overweight and obese women.

The rationale for use of Ulipristal Acetate as first line in emergency contraception: biological and clinical evidence

Ulipristal acetate (UPA) was licensed as an emergency contraceptive (EC) in Europe in 2009. By the end of May 2013, over 1.4 million courses had been used. The rationale for using UPA for EC in favor of the much more commonly used levonorgestrel (LNG) is based on data on efficacy, safety and side effects.

EFFICACY

In two large clinical trials among women presenting for EC up to 120 hours after unprotected sex, UPA was as effective as LNG at preventing pregnancy. When the two trials were combined in a meta analysis UPA was superior, almost halving the risk of pregnancy compared with LNG. Biomedical studies have shown that UPA inhibits or delays ovulation more effectively than LNG at a stage of the cycle when the risk of pregnancy is highest. Safety and side effects: UPA and LNG have similar side effect profiles and to date no serious adverse events have been attributed to use of UPA for EC. Data on pregnancies conceived in association with UPA use are reassuring. There is no evidence for teratogenesis or for any increased risk of ectopic pregnancy or miscarriage.

AVAILABILITY

Use of UPA will remain limited until it is available without a doctor's prescription.

Mechanisms of action of oral emergency contraception

This review gives an overview of the mechanisms of action of oral emergency contraception pills (ECPs), focusing on the levonorgestrel (LNG) and ulipristal acetate (UPA) containing ECPs. In vivo and in vitro studies have addressed the effect of EC on various possible targets. Based on these studies as well as on clinical trials it is clear that the efficacy of ECPs to prevent an unintended pregnancy depends on their mechanism of action as well as on their use in relation to the fertile window. While the main effect of both available ECPs is to prevent or delay ovulation the window of action for UPA is wider than that of LNG. This provides the biological explanation for the difference observed in clinical trials and the higher efficacy of UPA. Neither LNG nor UPA impairs endometrial receptivity or embryo implantation. Correct knowledge on the mechanism of action of ECPs is important to avoid overestimating their effectiveness and to advise women on correct use.

Physical and mental development of children after levonorgestrel emergency contraception exposure: a follow-up prospective cohort study

Levonorgestrel (LNG), a dedicated emergency contraception (EC) product, has been available over-the-counter in China for more than 14 yr. Although LNG-EC is considered to have no effects on the developing fetus if the contraceptive fails and pregnancy occurs, there have been a few studies specifically examining this issue. The purpose of this study was to compare the physical and mental development of children born after LNG-EC failure with that of a cohort of children born to mothers with no history of exposure to LNG or any teratogenic substances. A group of 195 children who were exposed to LNG-EC during their mothers' conception cycle (study group) were matched to a group of 214 children without exposure to LNG (control group). The physical and mental development of the children were evaluated and compared over a 2-yr period. There were four congenital malformations in the study group and three in the control group (2.1% vs. 1.4%, respectively, P > 0.05). Over the 2-yr follow-up period, there were no statistically significant differences between the two groups with respect to children's weight, height, head circumference, and intelligence scores, and the values of all parameters of both groups were similar to those of the national standards. In summary, LNG-EC has no effect on the physical growth, mental development, or occurrence of birth defects in children born from pregnancies in which EC failed.

A systematic review of effectiveness and safety of different regimens of levonorgestrel oral tablets for emergency contraception

BACKGROUND

Unintended pregnancy is a complex phenomenon which raise to take an emergency decision. Low contraceptive prevalence and high user failure rates are the leading causes of this unexpected situation. High user failure rates suggest the vital role of emergency contraception to prevent unplanned pregnancy. Levonorgestrel - a commonly used progestin for emergency contraception. However, little is known about its pharmacokinetics and optimal dose for use. Hence, there is a need to conduct a systematic review of the available evidences.

METHODS

Randomized, double-blind trials were sought, evaluating healthy women with regular menstrual cycles, who requested emergency contraception within 72 h of unprotected coitus, to one of three regimens: 1.5 mg single dose levonorgestrel, two doses of 0.75 mg levonorgestrel given 12 h apart or two doses of 0.75 mg levonorgestrel given 24 h apart. The primary outcome was unintended pregnancy; other outcomes were side-effects and timing of next menstruation.

RESULTS

Every trial under consideration successfully established the contraceptive effectiveness of levonorgestrel for preventing unintended pregnancy. Moreover, a single dose of levonorgestrel 1.5 mg for emergency contraception supports its safety and efficacy profile. If two doses of levonorgestrel 0.75 mg are intended for administration, the second dose can positively be taken 12-24 h after the first dose without compromising its contraceptive efficacy. The main side effect was frequent menstrual irregularities. No serious adverse events were reported.

CONCLUSIONS

The review shows that, emergency contraceptive regimen of single-dose levonorgestrel is not inferior in efficacy to the two-dose regimen. All the regimens studied were very efficacious for emergency contraception and prevented a high proportion of pregnancies if taken within 72 h of unprotected coitus. Single levonorgestrel dose (1.5 mg) can substitute two 0.75 mg doses 12 or 24 h apart. With either regimen, the earlier the treatment is given, the more effective it seems to be.

Levonorgestrel exposure to fathead minnows (Pimephales promelas) alters survival, growth, steroidogenic gene expression and hormone production

Human pharmaceuticals are commonly detected in the environment. Concern over these compounds in the environment center around the potential for pharmaceuticals to interfere with the endocrine system of aquatic organisms. The main focus of endocrine disruption research has centered on how estrogenic and androgenic compounds interact with the endocrine system to elicit reproductive effects. Other classes of compounds, such as progestins, have been overlooked. Recently, studies have investigated the potential for synthetic progestins to impair reproduction and growth in aquatic organisms. The present study utilizes the OECD 210 Early-life Stage (ELS) study to investigate the impacts levonorgestrel (LNG), a synthetic progestin, on fathead minnow (FHM) survival and growth. After 28 days post-hatch, survival of larval FHM was impacted at 462 ng/L, while growth was significantly reduced at 86.9 ng/L. Further analysis was conducted by measuring specific endocrine related mRNA transcript profiles in FHM larvae following the 28 day ELS exposure to LNG. Transcripts of 3β-HSD, 20β-HSD, CYP17, AR, ERα, and FSH were significantly down-regulated following 28d exposure to 16.3 ng/L LNG, while exposure to 86.9 ng/L significantly down-regulated 3β-HSD, 20β-HSD, CYP19A, and FSH. At 2,392 ng/L of LNG, a significant down-regulation occurred with CYP19A and ERβ transcripts, while mPRα and mPRβ profiles were significantly induced. No significant changes occurred in 11β-HSD, CYP11A, StAR, LHβ, and VTG mRNA expression following LNG exposure. An ex vivo steroidogenesis assay was conducted with sexually mature female FHM following a 7 day exposure 100 ng/L LNG with significant reductions observed in pregnenolone, 17α,20β-dihydroxy-4-pregnen-3-one (17,20-DHP), testosterone, and 11-ketotestosterone. Together these data suggest LNG can negatively impact FHM larval survival and growth, with significant alterations in endocrine related responses.