Association between levonorgestrel emergency contraception and the risk of ectopic pregnancy: a multicenter case-control study

Emergency contraception - A narrative review of literature

BACKGROUND

Emergency contraception includes several methods of contraception that can be used after unprotected sexual intercourse, after failure of any used method of contraception or in case of sexual abuse, to prevent pregnancy.

PURPOSE OF THE STUDY

The aim of the study was to analyze the available methods of emergency contraception, their mechanisms of action, efficacy, forms of administration, clinical applications and possible adverse effects.

MATERIAL AND METHOD

PubMed, Scopus and Cochrane datebases were searched for articles from 2010 to 2024 about emergency contraception.

RESULTS

The analyzed types of emergency contraception included single oral dose of ulipristal acetate, single oral dose of levonorgestrel and intrauterine system releasing levonorgestrel or copper intrauterine device. Taking emergency contraception in the optimum time according to the drug characteristics allows for avoiding pregnancy in more than 90% of cases (depending on the type of emergency contraception and time from unprotected intercourse). The analyzed literature shows that intrauterine copper intrauterine device is the most effective method of emergency contraception, also together with intrauterine system releasing levonorgestrel leading to the lowest rate of adverse effects.

CONCLUSIONS

Taking emergency contraception can result in various adverse effects, therefore it should be introduced after thorough analysis of woman's medical history, including gynecological and obstetric history and potential contraindications. Additionally, the patient should receive detailed information about the drug mechanism of efficacy and potential adverse effects.

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.

A systematic review and meta-analysis of the prevalence and association between levonorgestrel and ectopic pregnancy

BACKGROUND

The use of levonorgestrel emergency oral contraceptives (EOCs) is one of the factors that may be associated with ectopic pregnancy. We aimed to investigate the incidence of ectopic pregnancy in EOC users and the association between EOCs and ectopic pregnancy.

RESEARCH DESIGN AND METHODS

We searched for articles that provided the incidence of and the association between levonorgestrel EOCs and ectopic pregnancy in women of reproductive ages in CINAHL Complete, Medline, OpenDissertations, Scopus, Science Direct, and Thai Journal Online. The risk of bias was assessed by Risk Of Bias In Non-randomized Studies or Risk of Bias 2. A meta-analysis was conducted using the random-effects model.

RESULTS

We retrieved 1839 nonredundant articles from the systematic search. The meta-analysis showed that the prevalence of ectopic pregnancy was not statistically different from zero (pooled prevalence estimate = 0.029%; 95%CI: -0.006, 0.065; N = 9; I2 = 0) and rare. In addition, levonorgestrel EOCs increased the risk of ectopic pregnancy (OR = 6.17; 95%CI: 3.78, 10.08; N = 5; I2 = 43%).

CONCLUSIONS

Women with extrauterine or ectopic pregnancy had higher odds of using levonorgestrel emergency oral contraceptives than those with intrauterine pregnancy. However, the prevalence of ectopic pregnancy is rare.

Assessing the risk factors and management outcomes of ectopic pregnancy: A retrospective case-control study

Background

Ectopic pregnancy (EP) is the implantation of a fertilized egg outside the uterine cavity or in an unusual location. According to the clinical case reports, hormonal contraceptive failures may be related to emergency contraceptives and EP. EP may be treated medically, surgically, or expectantly. Currently, there is no consensus regarding whether a multiple- or double-dose regimen with methotrexate (MTX) or an additional dose could be more effective than a single-dose regimen.

Objective

This study aimed to assess risk factors and treatment outcomes for EP.

Materials and Methods

This case-control study was conducted in Tehran, Iran from March 2020 to March 2021. The case group was comprised of all EP-diagnosed cases (n = 191). Based on the levels of β-human chorionic gonadotropin, MTX was administered to stable individuals with no surgical indications. Risk factors were assessed through 2 control groups: intrauterine pregnancy (n = 190) and nonpregnant groups (n = 180).

Results

The medical treatment significantly improved with an extra dose of MTX, especially in individuals with higher β-human chorionic gonadotropin concentrations and gestational age > 7.5 wk (p = 0.002). Considering risk factors, it is assumed that hormonal contraceptive failures, including both oral and emergency contraceptives, may increase the EP likelihood (p < 0.001).

Conclusion

Based on our findings, we recommended an additional dose of MTX for subjects who are further along in their pregnancy. It is also concluded that failure of contraceptive pills increases the chances of EP.

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.

Ectopic Pregnancy Following Levonorgestrel Emergency Contraception: Report of Two Cases

Abstract Ectopic pregnancy (EP) is likely to occur as an unwanted complication after unprotected intercourse in spite of levonorgestrel emergency contraception (LNG-EC).   Its incidence has been increasing recently. We present 2 cases of tubal EP  after the oral use of levonorgestrel, treated by  laparoscopy.The first unruptured EP with unclear ultrasound findings, because of   uterine ventrofixation  after the caesarean section (CS) . The second case is a ruptured EP after LNG –EC   on day 24 of the period  with mild  haemoperitoneum with severe peritoneal irritation. The fundamental question is whether levonorgestrel participates in the etiology of EP. The etiology of EP involves many factors. Levonorgestrel mechanisms of action give us grounds to believe theoretically that it increases the risk of EP and participates as an etiological factor.  

The role of SK3 in progesterone-induced inhibition of human fallopian tubal contraction

BACKGROUND

Normal motor activity of the fallopian tube is critical for human reproduction, and abnormal tubal activity may lead to ectopic pregnancy (EP) or infertility. Progesterone has an inhibitory effect on tubal contraction; however, the underlying mechanisms remain unclear. Small-conductance calcium-activated K⁺ channel 3 (SK3) is abundantly expressed in platelet-derived growth factor receptor α positive (PDGFRα+) cells and was reported to be important for the relaxation of smooth muscle. The present study aims to explore the expression of SK3 in the human fallopian tube and its role in progesterone-induced inhibition of tubal contraction.

METHODS

We collected specimens of fallopian tubes from patients treated by salpingectomy for EP (EP group) and other benign gynecological diseases (Non-EP group). The expression of SK3 was detected by quantitative real-time polymerase chain reaction, western blot, immunocytochemistry, and immunohistochemistry analyses. Isometric tension experiments were performed to investigate the role of SK3 in progesterone-induced inhibition of tubal contraction.

RESULTS

The baseline amplitude and frequency of human fallopian tube contraction were both statistically lower in the EP group compared with the non-EP group. The expression levels of SK3 in different portions of fallopian tubes from the non-EP group were significantly higher than in those from the EP group. Progesterone had an inhibitory effect on tubal contraction, mainly on the amplitude, in both groups, and SK3 as well as other calcium-activated K⁺ channels may be involved. SK3-expressing PDGFRα (+) cells were detected in the human fallopian tube.

CONCLUSIONS

The expression of SK3 is lower in the EP group, and SK3 is involved in the progesterone-induced inhibition of human fallopian tube contraction.

Prevalence and determinants of ectopic pregnancy in Ethiopia: Systematic review and meta-analysis

Background:

Ectopic pregnancy is a life-threatening obstetric emergency, and is a major health problem for women of fertile age. Therefore, the aim of this systematic review and meta-analysis was to estimate the prevalence, determinant factors, and outcomes of ectopic pregnancy among fertile age women in Ethiopia.

Method:

International databases (MEDLINE/Pub Med, Hinari, Scopus, Google scholar, African journals, and literatures were searched and nine eligible cross sectional and two case control studies were included in this systematic review and meta-analysis. Eggers test and funnel plot were computed to check publication bias across the studies. Publication bias was computed using a funnel plot and eggers test. Heterogeneity of the studies was checked using Cochrane Q-test and I2 statistic.

Results:

The pooled prevalence of ectopic pregnancy in Ethiopia was 3.61% (95%CI: 2.24–4.98, I2 = 89.2.0%, p < 0.001). Having cesarean section scar (AOR = 7.44, 95%CI: 5.48–10.09), single marital status (AOR = 5.71, 95%CI: 4.76–6.85), history of sexually transmitted infection (AOR = 4.68, 95%CI: 3.04–7.19), history of abortion (AOR = 3.89, 95%CI: 3.35–4.52), history of ectopic pregnancy (AOR = 5.74, 95%CI: 3.81–8.65), and emergency contraceptive use (AOR = 8.72, 95%CI: 2.90–26.20) were the determinant factors for the occurrence of ectopic pregnancy.

Conclusion:

This systematic review and meta-analysis showed that the prevalence of ectopic pregnancy was high in Ethiopia. Thus, educating women to limit the number of sexual partners, smoking cessation, using a condom during sex helps prevent sexually transmitted infections and the risk of pelvic inflammatory disease is crucial.

A Systematic Review and Meta-analysis of the Adverse Effects of Levonorgestrel Emergency Oral Contraceptive

INTRODUCTION

The levonorgestrel oral emergency contraceptive is well tolerated and effective, however its use is still limited, mainly due to safety concerns.

OBJECTIVE

This systematic review and meta-analysis aimed to summarize current evidence regarding the adverse events, and their prevalence, reported during the use of oral levonorgestrel emergency contraceptives.

METHODS

Four electronic databases and the US FDA Adverse Event Reporting System (FAERS) Public Dashboard were searched. Studies that reported or investigated safety outcomes or adverse reactions during the use of levonorgestrel as an emergency oral contraceptive were included. Data on study design, demographics of levonorgestrel and the control cohort, and reported adverse effects were extracted.

RESULTS

A total of 47 articles were included in this systematic review, from which it was shown that most of the adverse reactions were common and not serious. Uncommon adverse reactions identified included anorexia, ectopic pregnancy, exanthema, chloasma, miscarriage, and weight gain. Multiple serious adverse events, including convulsion, ectopic pregnancy, febrile neutropenia, stroke, abdominal hernia, anaphylaxis, cancer, ovarian cyst rupture, serious infections, and suicidal ideation, were reported. In addition, the prevalence of adverse events after a levonorgestrel 0.75 mg two-dose regimen and a levonorgestrel 1.5 mg single-dose regimen were not statistically different (p > 0.05).

CONCLUSIONS

The most common adverse effects of levonorgestrel were not serious. This systematic review shows that data regarding the adverse reactions of repeated use of levonorgestrel are scarce. Studies on the multiple uses of levonorgestrel emergency contraception are still required to ensure its safety.

The association between mitochondrial DNA copy number, telomere length, and tubal pregnancy

Growing evidence has demonstrated association between the occurrence of tubal ectopic pregnancy (TP) and oxidative stress (OS) status, in which mitochondria and telomeres play important roles. However, little is known about the underlying correlation between TP and the mitochondrial DNA copy number (mtDNAcn) or telomere length (TL) abnormalities. In this study, we found OS level was elevated in TP patients. We hierarchically detected the relative mtDNAcn and TL of villi from normal pregnancy (NP) and TP samples according to different gestational age, fetal sex, maternal age, and BMI. The results revealed that the relative mtDNAcn was significantly lower in the villi in the TP group compared with the NP cohort, which was negatively correlated with OS status. In the NP group, the mtDNAcn in the female subgroup was apparently lower than that in the male subgroup, while no statistical difference was found in the mtDNAcn in the TP group between the female and male subgroups. Moreover, the relative TL in the TP group was at a similar level to the NP group, and no statistical correlation was observed between relative TL and OS level. In summary, our findings indicate that the abnormal level of mtDNAcn rather than TL is correlated with TP, which provides new insights into the mechanism of TP.

TRPV4 is involved in levonorgestrel-induced reduction in oviduct ciliary beating

Previous studies revealed the increasing risk of tubal pregnancy following failure of levonorgestrel (LNG)‐induced emergency contraception, which was attributed to the reduced ciliary motility in response to LNG. However, understanding of the mechanism of LNG‐induced reduction in the ciliary beat frequency (CBF) is limited. The transient receptor potential vanilloid (TRPV) 4 channel is located widely in the female reproductive tract and generates an influx of Ca²⁺ following its activation under normal physiological conditions, which regulates the CBF. The present study aimed to explore whether LNG reduced the CBF in the Fallopian tubes by modulating TRPV4 channels, leading to embryo retention in the Fallopian tubes and subsequent tubal pregnancy. The study provided evidence that the expression of TRPV4 was downregulated in the Fallopian tubes among patients with tubal pregnancy and negatively correlated with the serum level of progesterone. LNG downregulated the expression of TRPV4, limiting the calcium influx to reduce the CBF in mouse oviducts. Furthermore, the distribution of ciliated cells and the morphology of cilia did not change following the administration of LNG. LNG‐induced reduction in the CBF and embryo retention in the Fallopian tubes and in mouse oviducts were partially reversed by the progesterone receptor antagonist RU486 or the TRPV4 agonist 4α‐phorbol 12,13‐didecanoate (4α‐PDD). The results indicated that LNG could downregulate the expression of TRPV4 to reduce the CBF in both humans and mice, suggesting the possible mechanism of tubal pregnancy. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Risk factors for ectopic pregnancy in a population of Cameroonian women: A case-control study

OBJECTIVE

To identify the risk factors for ectopic pregnancy (EP) in a population of Cameroonian women.

SAMPLE AND METHODS

We performed a matched case-control study; 88 women with diagnosed EP (cases), and 176 women with first trimester intrauterine pregnancy (IUP) (controls), who underwent questionnaires. Odds Ratio (OR) and 95% confidence intervals (CIs) were calculated and adjusted for potential confounding factors via multivariate logistic regression analysis.

RESULTS

Of the fifteen identified risk factors, 4 were independently associated with increased odds of EP: prior pelvic inflammatory disease (PID) (adjusted odds ratio [AOR] 13.18; 95% CI 6.19-27.42), followed by current use of levonorgestrel-only pills for emergency contraception (LNG-EC) (AOR 10.15; 95% CI 2.21-46.56), previous use of depot medroxyprogesterone acetate (DMPA) (AOR 3.01; 95% CI 1.04-8.69) and smoking at the time of conception (AOR 2.68; 95% CI 1.12-6.40).

CONCLUSION

The present study confirms the wide variety of EP's risk factors. Moreover, some new findings including current use of LNG-EC, previous use of DMPA, smoking at the time of conception are noteworthy. Thus, in our limited resources country where prevention remains the cornerstone for reducing EP chances of occurrence, clinicians should do enough counselling, especially to women with known risk factors. The necessity to facilitate access to more equipment to enable early diagnosis of EP is very crucial and should be seriously considered, in order to reduce the burden of EP in Cameroonian women.

Ectopic pregnancy following oral levonorgestrel emergency contraception use

Levonorgestrel is used worldwide as an emergency oral contraceptive. There have been occasional reports of ectopic pregnancy after oral levonorgestrel use. We present a case of ectopic tubal pregnancy after the use of oral levonorgestrel as an emergency contraceptive in a 37-year-old woman with a history of treatment for Chlamydia trachomatis infection. She conceived after sexual intercourse on menstrual day 14 of the first menstrual cycle following a normal delivery. After salpingectomy for this right tubal pregnancy, her following pregnancy was an ectopic pregnancy in the contralateral tube, which was treated with laparoscopic salpingectomy. Histopathological examination revealed endometriosis. We should be aware of ectopic pregnancy even after emergency contraceptive use, especially in patients with risk factors, such as Chlamydia infection and endometriosis. Because the efficacy of levonorgestrel decreases after ovulation, we should check the stage of the cycle before prescription.

Left-Right Asymmetry of Tubal Pregnancy: A 12-Year Retrospective Hospital-Based Study

STUDY OBJECTIVE

To investigate whether there are left-right asymmetries, factors affecting lateral dominance, and clinical feature differences in the left and right sides of tubal pregnancy (TP).

DESIGN

Retrospective study (Canadian Task Force classification II-2).

SETTING

International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University.

PATIENTS

Patients (n = 6186) with TP treated surgically.

INTERVENTIONS

We used data from the digital medical records system of the hospital. Women diagnosed with ectopic pregnancy(EP) between January 2005 and December 2016 in the inpatient department of gynecology were included. All data from the medical files were obtained retrospectively, including demographic characteristics; reproductive, gynecologic, and surgical history; clinical features; and treatment. Patients who were previously treated by salpingectomy or nonsurgical management and those with unknown-site EP or non-TPs were excluded.

MEASUREMENTS AND MAIN RESULTS

The overall frequency of right-sided TP was 54.48% (3370/6186), which is significantly higher than 50% (p < .001, binominal test). The proportion of right-sided TPs decreased with age (p for trend = .007) and from the proximal (interstitial) end to the distal (fimbrial) end of the tube (p for trend = .017). Of the TP patients with a corpus luteum, we found the corpus luteum was more frequently located in the right ovary (p < .001) and in the contralateral ovary to the TP side in 41.38% of cases. However, tubal rupture was more frequent in left TP than the in right TP (p = .005).

CONCLUSION

The left-right asymmetries of TP include right-side dominance and the clinical feature differences between the 2sides of TP.

Effects of Levonorgestrel and progesterone on Oviductal physiology in mammals

BACKGROUND

Our previous study indicated that emergency contraception, including levonorgestrel and progesterone, could lead to ectopic pregnancy following contraception failure. However, our understanding of the effects of levonorgestrel and progesterone on oviductal physiology is limited.

METHODS

The receptivity of the fallopian tubal epithelium after levonorgestrel and progesterone treatment was examined through western blots for receptivity markers and JAr-spheroid-fallopian tubal epithelial cell attachment assays. The ciliary beat frequency was analyzed using an inverted bright-field microscope. Furthermore, an in vivo animal model of embryo-tubal transplantation was also studied to determine the effects of levonorgestrel- and progesterone-induced ciliary beat reduction.

RESULTS

Our results showed that levonorgestrel and progesterone did not change the levels of fallopian tubal epithelial cell receptive markers, including LIF, STAT3, IGFBP1, ITGB3, MUC1, and ACVR1B, or affect JAr-spheroid implantation. However, levonorgestrel and progesterone reduced the ciliary beat frequency in fallopian tubes in a dose-dependent manner. An in vivo model also showed that levonorgestrel and progesterone could lead to embryo retention in the oviducts.

CONCLUSIONS

These findings show that levonorgestrel and progesterone can reduce the ciliary beat frequency without altering receptivity, indicating a possible mechanism for progesterone- or levonorgestrel-induced tubal pregnancy.

Emergency Medicine Myths: Ectopic Pregnancy Evaluation, Risk Factors, and Presentation

BACKGROUND

Ectopic pregnancy (EP) is an important cause of morbidity and mortality in females of reproductive age. Proper diagnosis and treatment are critical, as complications such as rupture, hemorrhagic shock, and even death can occur.

OBJECTIVE

EP is a condition emergency physicians are trained to detect, yet there are multiple myths concerning its evaluation and diagnosis. This article reviews several of these myths in order to improve emergency department (ED) evaluation and diagnosis.

DISCUSSION

EP is a difficult diagnosis and may be missed on initial ED visit. While the diagnosis is often delayed simply due to very early presentations, it can also be missed because patients may not have all the same risk factors or demonstrate the same symptoms. They may also not demonstrate the same serum B-human chorionic gonadotropin levels and trends or have the same ultrasound findings at equivalent gestational ages. Some patients with early EP may have positive ultrasound findings with serum β-hCG levels under a defined discriminatory zone (DZ). On the other hand, some patients with an early viable intrauterine pregnancy may have no visible findings on initial ultrasound, but have serum β-hCG (quantitative) levels well above the DZ. Although rare, EP has even been demonstrated in women with negative urine β-hCG tests or low serum β-hCG levels.

CONCLUSIONS

While EP may be a challenging diagnosis, understanding the myths surrounding EP may help emergency physicians consider it, even when patient risk factors, symptoms, or ED laboratory or imaging studies do not initially or easily define the diagnosis.

Association between knowledge about levonorgestrel emergency contraception and the risk of ectopic pregnancy following levonorgestrel emergency contraception failure: a comparative survey

Objective

To study the association between knowledge about levonorgestrel emergency contraception (LNG‐EC) and the risk of ectopic pregnancy (EP) following LNG‐EC failure.

Methods

This study included 600 women who had visited the hospital with LNG‐EC failure. Of these, 300 with EP and 300 with intrauterine pregnancy (IUP) were recruited to the EP group and IUP group respectively. The participants were interviewed face‐to‐face using a standardized questionnaire.

Main Outcome Measures

Pearson's chi‐square tests and t‐test were used to compare the sociodemographic characteristics, reproductive and gynecological history, surgical history, previous contraceptive experience, and answers to 10 questions concerning the knowledge about LNG‐EC.

Results

Those who gave incorrect answers to the question regarding the basic mechanism and specific method of levonorgestrel emergency contraceptive pills (LNG‐ECPs) were at a higher risk of EP after LNG‐EC failure. Women who did not strictly follow instructions or advice from healthcare professionals were more likely to subsequently experience EP (p < 10⁻⁴). Women with LNG‐EC failure reported friends/peers, TV, and Internet as the main sources of information. No difference was observed with regard to the sources of knowledge on LNG‐EC (p = 0.07).

Conclusions

The results illustrate the importance of strictly following the doctor's guidance or drug instructions when using LNG‐ECPs. The media should be used to disseminate information about responsible EC, and pharmacy staff should receive regular educational training sessions in this regard. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Safety data for levonorgestrel, ulipristal acetate and Yuzpe regimens for emergency contraception

The World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) provide recommendations for use of emergency contraceptive pills (ECPs), including levonorgestrel (LNG) and combined oral contraceptives (COCs). A new ECP formulation, ulipristal acetate (UPA), is now available worldwide. To determine whether LNG, UPA or COC (Yuzpe) ECPs are safe for women with certain characteristics or medical conditions, we searched the PubMed and Cochrane databases for articles published from date of inception until May 2015 pertaining to the safety of LNG, UPA or Yuzpe ECP use. For direct evidence, we considered studies that looked at safety outcomes among women with certain medical conditions or characteristics taking ECPs compared with women not taking ECPs. For indirect evidence, we considered studies that reported pharmacokinetic (PK) data for ECP use among women with certain medical conditions or characteristics and studies that reported safety outcomes among healthy women taking ECPs. Five studies provided direct evidence; of these five studies, four examined LNG or Yuzpe use among pregnant or breastfeeding women, and one reported risk of ectopic pregnancy among women repeatedly using LNG ECPs. Poor pregnancy outcomes were rare among pregnant women who used LNG or Yuzpe ECPs during the conception cycle or early pregnancy. Breastfeeding outcomes did not differ between women exposed to LNG ECP and those unexposed, and there was no increased risk of ectopic pregnancy versus intrauterine pregnancy after repeated use of LNG ECPs compared with nonuse. Forty-five studies provided indirect evidence. One PK study demonstrated that LNG passes into breastmilk but in minimal quantities. In addition, nine studies examined pregnancy outcomes following ECP failure among healthy women, and 35 articles reported adverse events. Studies suggest that serious adverse events are rare among women taking any of these ECP formulations.

IMPLICATIONS

Evidence on safety of ECPs among women with characteristics or medical conditions listed within WHO and CDC family planning guidance is limited. However, both direct and indirect evidence for our study question did not suggest any special safety concerns for the use of ECPs among women with particular medical conditions or personal characteristics, such as pregnancy, lactation or frequent ECP use.