A Longitudinal Multilevel Analysis of the Effects of Contraceptive Failures on Unintended Pregnancies among Women in Urban Nigeria.

Unintended pregnancy is a global public health concern. However, the effect of contraceptive failure on unintended pregnancy remains unclear in Nigeria. We undertook a longitudinal analysis to examine the effect of contraceptive failure on unintended pregnancy among urban women in Nigeria. We used panel data from the Nigerian Urban Reproductive Health Initiative. The Measurement, Learning and Evaluation program conducted the surveys among a cohort of women aged 15-49 who were first interviewed at baseline in 2010/2011 and followed up at endline in 2014/2015. Analytic sample was 4140 women aged 15-49 who ever used contraceptives. We fitted three-level multilevel binary logistic regression models estimated with GLLAMM. The study established evidence that there is a significant effect of contraceptive failure on unintended pregnancy among urban women in Nigeria. The positive effect of between-person contraceptive failure indicates that respondents who experienced more contraceptive failure than the average in the sample had 5.26 times higher odds of unintended pregnancy (OR = 5.26; p-value < 0.001). Results also established a significant effect of within-person contraceptive failures among the respondents. Findings suggest there is evidence of a significant longitudinal effect of contraceptive failure on unintended pregnancy in urban Nigeria. Efforts to reduce unintended pregnancy must include interventions to address the problem of contraceptive failure among urban women in Nigeria.

Is the multinational, surveillance PRO-E2 study informative for all countries? The Italian data on VTE and contraceptive effectiveness.

PURPOSE: To evaluate whether the thromboembolic risk and contraceptive effectiveness of NOMAC-E2 observed in the PRO-E2 study can be extended to each participating country, as lifestyle, cardiovascular risk factors and prescribing habits may differ geographically. This analysis was performed on the PRO-E2 Italian subpopulation, where smoking habit and women over 35 years were more prevalent compared with the overall study population. MATERIALS AND METHODS: Data from NOMAC-E2 or levonorgestrel-containing COCs (COCLNG) new users were descriptively analysed. Incidence rates of thrombosis (events/10,000 women-years [WY]) and the Pearl Index (pregnancies/100 WY) were calculated. RESULTS: Overall, 11,179 NOMAC-E2 and 8,504 COCLNG users were followed up to 2 years (34,869 WY). The NOMAC-E2 cohort included more women over 35 vs. COCLNG (37.7% vs. 31.8%; p = 0.001). A comparable low risk of combined deep venous thrombosis of lower extremities (DVT) and pulmonary embolism (PE) was observed in NOMAC-E2 (1.7/10,000 WY; 95% CI: 0.21-6.2) and COCLNG users (6.6/10,000 WY; 95% CI: 2.4-14.4). Similar results were obtained by considering all thromboembolic events (VTE). Unintended pregnancies did not differ between NOMAC-E2 (0.12/100 WY; 95% CI: 0.06-0.21) and COCLNG (0.15/100 WY; 95% CI: 0.08-0.26) cohorts. CONCLUSION: Despite the higher age and tobacco use, findings from the Italian subpopulation were broadly consistent with overall PRO-E2 results, confirming a similar low thromboembolic risk and high contraceptive effectiveness of NOMAC-E2 and COCLNG. SHORT CONDENSATION: This subgroup analysis of the PRO-E2 study provides comprehensive epidemiological data on the use of combined oral contraceptives in a large Italian cohort, with a higher prevalence of women over 35 years and smokers. The study confirms the low thromboembolic risk and high contraceptive effectiveness of NOMAC-E2 pill.

O uso dos métodos anticoncepcionais por estudantes de Medicina: uma revisão narrativa / Medical students' use of contraceptive methods: a narrative review

Anticoncepção são todas as técnicas e métodos utilizados para evitar a concepção. Os estudantes de Medicina se destacam nesse contexto, por representarem uma população em um período no qual a gravidez e doenças sexualmente transmissíveis são emergenciais. Logo, este estudo analisou a eficácia dos métodos contraceptivos na comunidade acadêmica médica e verificou se há ou não diferença na taxa de eficácia, em comparação com a população em geral. Sendo assim, realizou- -se uma revisão narrativa e encontraram-se 2.182 artigos; desses, 1.513 cumpriram o critério de inclusão, porém somente quatro artigos atendiam a todos os critérios e foram utilizados. A conclusão do estudo foi de que a taxa de Pearl é maior na população estudada devido ao mau uso dos contraceptivos, necessitando da melhora na qualidade da educação sexual nas universidades de Medicina ao redor do mundo, a fim de se evitarem a perpetuação da má utilização de contraceptivos e a desinformação no meio acadêmico médico.

Contraception is all the techniques and methods that are used to prevent conception. Medical students stand out in this context because they represent a population in a period in which pregnancy and sexually transmitted diseases are emergencies. Therefore, this study analyzed the effectiveness of contraceptive methods in the medical academic community and verified whether or not there is difference in the rate of effectiveness compared to the general population. A narrative review was conducted and 2,182 articles were found, of these 1,513 met the inclusion criteria, but only four articles met all the criteria and were used. The conclusion of the study was that Pearl's rate is lower in the studied population due to the misuse of contraceptives, requiring improvement in the quality of sex education in medical universities around the world in order to avoid perpetuation of misuse of contraceptives and misinformation in the medical academic environment.

NOMAC-E2 shows a better contraceptive effectiveness than LNG combined oral contraceptives in women under 25: real-world PRO-E2 study.

Objective: To investigate unintended pregnancy and changes in mood, acne, and weight in NOMAC-E2 vs levonorgestrel-containing COC (COCLNG) users under 25 years.Methods: In this large, observational study, new users (first-ever users of an eligible COC or restarting with the same or a new eligible COC after a break of at least 2 months) of NOMAC-E2 and COCLNG were recruited in 12 countries in Europe, Australia, and Latin America and followed up via questionnaires for up to 2 years. Unintended pregnancy was expressed by the Pearl Index (PI; contraceptive failures/100 women-years). Crude (HRcrude) and adjusted hazard ratios (HRadj) were calculated. Mood and acne changes were defined as change of score from baseline. Weight change was defined as percent change of body weight.Results: Overall, 12,829 NOMAC-E2 users and 17,095 COCLNG users under 25 were followed-up. The risk of unintended pregnancy was statistically significantly lower in the NOMAC-E2 cohort; confirmed events: 30 NOMAC-E2 (PI 0.24; 95% CI, 0.16-0.35) vs 94 COCLNG (PI 0.51; 95% CI, 0.41-0.62). The HRcrude for unintended pregnancy comparing NOMAC-E2 to COCLNG was 0.47 (95% CI, 0.31-0.71) and the HRadj was 0.52 (95% CI, 0.34-0.78). No differential effect on acne, mood, and weight was observed between cohorts.Conclusions: NOMAC-E2 shows a significantly better contraceptive effectiveness in young women and has no differential effect on acne, mood, and weight compared to COCLNG.

Métodos anticonceptivos de larga duración (LARC): características de las usuarias, tasa de continuidad y efectividad / Long-Acting Reversible Contraceptive (LARC) methods: User characteristics, effectiveness, and continuation rates

Antecedentes: Los métodos anticonceptivos reversibles de larga duración (LARC) proporcionan una anticoncepción larga y reversible. Incluyen dispositivos intrauterinos (DIU) e implantes subdérmicos. Material y métodos: Estudio observacional longitudinal retrospectivo desde enero de 2017 a diciembre de 2019 incluyendo usuarias de LARC del Departamento de Salud de Elche. Se realizaron análisis descriptivos de: características de las pacientes, complicaciones postinserción, efectos no deseados y motivo de abandono, utilizando Kruskal-Wallis, ANOVA o chi-cuadrado en los análisis comparativos según la variable. Se analizaron las probabilidades de abandono tras 18meses mediante curvas Kaplan-Meier y se compararon mediante test Log-Rank. Se evaluó la razón de riesgo de las alteraciones del patrón de sangrado en las probabilidades de abandono mediante modelo de riesgos proporcionales de Cox. Resultados: Se incluyeron 605 usuarias de LARC, generalmente de raza blanca, multíparas y con pareja sexual estable. Las complicaciones más observadas fueron expulsión del DIU (4%) y hematoma cutáneo en la zona de inserción del implante (42,1%). El efecto no deseado más notificado fue el cambio del patrón de sangrado (26,8%) y su aparición aumentó el riesgo de interrupción del método (HR=1,76; IC95%: 1,15-2,68). Tras 18meses de uso, la tasa de continuidad fue del 86,9% (mayor para DIU-LNG 52mg) y la efectividad fue del 99,60% (resultado de 2embarazos con el uso de DIU-Cu). Conclusiones: Dado que los LARC son los métodos anticonceptivos reversibles más efectivos y con mayores tasas de continuación, deberían ser los métodos de primera línea ofrecidos a todas las mujeres que no presenten contraindicaciones.(AU)

Background: Long-Acting Reversible Contraceptive (LARC) methods provide long and reversible contraceptive effects. They include intrauterine devices (IUDs) —copper-containing IUD or levonorgestrel-releasing IUDs— and subdermal implant. Material and methods: A longitudinal observational retrospective study between January 2017 and December 2019 in which clinical records of users of LARC methods of the Elche Health Department were reviewed. Descriptive analyses were performed to describe user characteristics, post insertion problems, unwanted effects, and reasons for discontinuation; Kruskal-Wallis, ANOVA, and Chi-square were performed to compare these variables among different LARC methods, where appropriate. Kaplan-Meier survival curves were constructed to estimate continuation rates and the logrank test was applied for statistical comparisons. Cox proportional hazard models were used to estimate the hazard ratio (HR) for risk of contraceptive method discontinuation due to abnormal bleeding patterns. Results: Were included 605 LARC method users. These women were generally white, multiparous, and in stable relationships. The most common complications were IUD expulsion (4%) and haematoma at the implant site (42.1%). The main side effect was a change in bleeding patterns (26.8%) and was associated with premature removal (HR=1.76; 95%CI: 1.15-2.68). After 18months of use, the continuation rate was 86.9% (significantly higher for LNG-IUD 52mg) and effectiveness was 99.60% (result of 2 unintended pregnancies with use of copper-containing IUDs). Conclusions: Given that LARC methods have the highest rates of contraceptive efficacy and continuation, these methods should be the first-line contraceptive methods offered to patients without contraindications.(AU)

Exploring rise of pregnancy in Bangladesh resulting from contraceptive failure.

The objective of this study was to determine how changes in pre-pregnancy contraceptive methods used between 2011 and 2017/18 contributed to the changes in pregnancy resulting from contraceptive methods failure in Bangladesh. We used 2011 and 2017/18 Bangladesh Demographic and Health Survey data. Pre-pregnancy contraceptive methods failure was our outcome of interest, which was determined using women's response about whether they became pregnant while using contraceptives before the most recent pregnancy. The year of the survey was the main explanatory variable. Descriptive statistics were used to describe the characteristics of the respondents. The difference in contraceptive methods failure across the socio-demographic characteristics was assessed by Chi-squared test. Multilevel poison regressions were used to determine the changes in the prevalence ratio of contraceptive methods failure across the survey years. Contraceptive methods failure rate increased between the surveys, from 22.8% in 2011 to 27.3% in 2017/18. Also, male condom use increased by 2.8%, while withdrawal/periodic abstinence and/or other methods decreased by 2.9%. The failure rates in these two categories of contraceptive methods increased substantially by 4.0% and 9.0%, respectively. Compared to the 2011 survey, the prevalence ratio (PR) of contraceptive methods failure was 20% (PR 1.2, 95% CI 1.1-1.3) high in the 2017/18 survey. This PR declined 13% (PR 1.1, 95% CI 1.04-1.2) once the model was adjusted for women's and their partner's characteristics along with the last contraceptives used. This study provides evidence of increasing rates of pregnancy due to contraceptive failure in Bangladesh. Given that this type of pregnancy is known to cause adverse pregnancy outcomes, including abortion, pregnancy complications, maternal and early child morbidity and mortality, policy and programs are needed to reduce its prevalence. Effective coordination between the contraception providers at the healthcare facilities and the households and a proactive role of family planning workers to make couples aware of the effective use of contraceptives are recommended.

Factors Associated with Failed Contraception in Women Attending Level One Hospitals in Lusaka, Zambia

Background: Unintended pregnancy is a major public health concern due to its impact on maternal morbidity and mortality. Contraceptive failure is one of the causes of unintended pregnancy. Data on factors associated with contraceptive method failure is scarce. This study therefore aimed to explore factors associated with contraceptive failure. Methodology: Unmatched case-control study was conducted at five Level One Hospitals in Lusaka. Convenience sampling was used to enrol 108 cases for whom pregnancy occurred while on a modern contraceptive method and 108 hospital-based controls who were on a modern contraceptive method and not pregnant. Binary and multiple logistic regressions were utilized for assessment of factors associated with failed contraception. Results: Among the 108 cases, 46 (42.6%), 40 (37%), 17 (15.7%) and 1 (0.9%) were on the oral contraceptive pill, injectable, implant and intrauterine device contraception methods respectively while 2 (1.9%) were on barrier and emergency contraceptive methods respectively. The odds of contraceptive failure when using the oral contraceptive pill was more than 7 times (AOR 7.790, 95% CI 1.210-50.161, p=0.031). Those who had contraception failure were more than 3 times more likely to be younger than 30 years old compared to those whose contraceptive method did not fail (AOR 3.559, 95% CI 1.100-11.521, p=0.034 and AOR 3.596, 95% CI 1.354-9.550, p=0.010 respectively for age groups 18-24 years and 24-30 years old). Other factors associated with higher odds of contraceptive failure were duration of marriage greater than one year, with the highest odds in those married for more than 10 years (AOR 9.744, 95% CI 2.232-42.537, p=0.002), higher social support (AOR 2.402, 95% CI 1.085-5.321, p=0.031), multiparity (AOR 15.299, 95% CI 3.034- 77.151, p=0.001), and duration of use of antecedent contraception method of more than 2-3 years (AOR 4.913, 95% CI 1.662-14.526, p=0.004). Conclusion: The oral contraceptive pill, younger age, marriage duration of more than one year and contraceptive use more than three years were associated with contraceptive failure. Good messaging and counseling on usage of the oral contraceptive pill are recommended.

Aconselhamento contraceptivo para o paciente transgênero designado mulher ao nascimento / Contraceptive counseling for the transgender patient designated female at birth

Apesar de 0,7% da popul ação brasileira se identificar como transgênero, não existe treinamento para que o profissional de saúde realize um acolhimento de maneira integral a esse paciente, incluindo a discussão do planejamento reprodutivo. O uso de testosterona promove amenorreia nos primeiros meses de uso, entretanto esse efeito não garante eficácia contraceptiva e, consequentemente, aumenta os riscos de uma gravidez não planejada. Trata-se de uma revisão integrativa com o objetivo de avaliar e organizar uma abordagem do aconselhamento contraceptivo na população transgênero que foi designada mulher ao nascimento. Realizou-se busca estratégica em PubMed e Embase, bem como em guidelines internacionais, sobre cuidados à população transgênera. De 88 artigos, 11 foram utilizados para desenvolver o modelo de aconselhamento contraceptivo. O modelo segue as seguintes etapas: (1) Abordagem das informações relacionadas à necessidade de contracepção; (2) Avaliação das contraindicações ao uso dos métodos contraceptivos (hormonais e não hormonais); (3) Efeitos colaterais e possíveis desconfortos associados ao uso do contraceptivo. O modelo de aconselhamento contraceptivo é composto de 20 questões que abordam as indicações e contraindicações ao uso desses métodos e um fluxograma que auxilia na escolha entre os métodos permitidos ao paciente de acordo com a sua necessidade.(AU)

Cambios en el uso de anticonceptivos, embarazos no planificados e hijos en adolescentes chilenas entre 1997 y 2018 / Changes in the use of contraceptives, unplanned pregnancies and children in Chilean adolescents between 1997 and 2018

INTRODUCCIÓN: El embarazo en las adolescentes ha persistido como un problema de salud pública y social en Chile, afectando a las adolescentes más vulnerables y reflejando las desigualdades. OBJETIVO: Describir los cambios en el uso de anticonceptivos, embarazos no planificados e hijos en adolescentes chilenas entre 1997 y 2018. MÉTODO: Estudio ecológico de series temporales entre los años 1997 y 2018. Se midió la asociación entre variables sociodemográficas y efectividad del método anticonceptivo para los años 2006 y 2018, mediante la prueba estadística de Rao-Scott. Se estimaron tendencias del porcentaje de uso de métodos anticonceptivos según su eficacia y presencia de embarazos no planificados e hijos con modelos de regresión lineal (método de Prais-Winsten). RESULTADOS: Se observó un aumento en la frecuencia de adolescentes sexualmente activas y en el uso de anticonceptivos, especialmente píldoras e inyectables. La serie temporal de uso de anticonceptivos fue no estacionaria, la tendencia fue creciente (coeficiente: 4,59; intervalo de confianza del 95% [IC95%]: 3,43-5,74; p = 0,001), aumentando 4,59% cada 3 años. Las series de embarazos no planificados y tener hijos fueron series temporales no estacionarias y ambas presentaron una tendencia decreciente (coeficiente: −4,78; IC95%: −6,32 a −3,24; p = 0,002; y coeficiente: −3,93; IC95%: −6,18 a −1,68; p = 0,008), disminuyendo un 4,78% y un 3,93%, respectivamente, cada 3 años. CONCLUSIONES: El aumento en el uso de anticonceptivos en adolescentes ha ido unido a una importante disminución en los embarazos no planificados y los hijos en esta población.

INTRODUCTION: Adolescent pregnancy has persisted as a public and social health problem in Chile, affecting the most vulnerable adolescents and reflecting inequalities. OBJECTIVE: To describe the changes in the use of contraceptives, unplanned pregnancies and children in Chilean adolescents between 1997 and 2018. METHOD: Ecological study of time series between the years 1997 and 2018. The association between sociodemographic variables and the effectiveness of the contraceptive method for the years 2006 and 2018 was measured using the Rao-Scott statistical test. Trends in the percentage of use of contraceptive methods were estimated according to their efficacy and presence of unplanned pregnancies and children with linear regression models (Prais-Winsten method). RESULTS: An increase in the frequency of sexually active adolescents and the use of contraceptives, especially pills and injectables, was observed. The time series of contraceptive use was non-stationary, the trend was increasing (coefficient: 4.59; 95% confidence interval [95% CI]: 3.43-5.74; p = 0.001), increasing 4.59% every three years. The time series, unplanned pregnancies and having children were non-stationary time series, both showed a decreasing trend (coefficient: −4.78; 95%CI: −6.32 to −3.24; p = 0.002; and coefficient: −3.93; 95% CI: −6.18 to −1.68; p = 0.008), decreasing 4.78% and 3.93%, respectively, every 3 years. CONCLUSIONS: The increase in the use of contraceptives in adolescents has been linked to a significant decrease in unplanned pregnancies and children in this population.

A Semimechanistic Pharmacokinetic Model for Depot Medroxyprogesterone Acetate and Drug-Drug Interactions With Antiretroviral and Antituberculosis Treatment.

Depot medroxyprogesterone acetate is an injectable hormonal contraceptive, widely used by women of childbearing potential living with HIV and/or tuberculosis. As medroxyprogesterone acetate is a cytochrome P450 (CYP3A4) substrate, drug-drug interactions (DDIs) with antiretroviral or antituberculosis treatment may lead to subtherapeutic medroxyprogesterone acetate concentrations (< 0.1 ng/mL), resulting in contraception failure, when depot medroxyprogesterone is dosed at 12-week intervals. A pooled population pharmacokinetic analysis with 744 plasma medroxyprogesterone acetate concentrations from 138 women treated with depot medroxyprogesterone and antiretroviral/antituberculosis treatment across three clinical trials was performed. Monte Carlo simulations were performed to predict the percentage of participants with subtherapeutic medroxyprogesterone acetate concentrations and to derive alternative dosing strategies. Medroxyprogesterone acetate clearance increased by 24.7% with efavirenz coadministration. Efavirenz plus antituberculosis treatment (rifampicin + isoniazid) increased clearance by 52.4%. Conversely, lopinavir/ritonavir and nelfinavir decreased clearance (28.7% and 15.8%, respectively), but lopinavir/ritonavir also accelerated medroxyprogesterone acetate's appearance into the systemic circulation, thus shortening the terminal half-life. A higher risk of subtherapeutic medroxyprogesterone acetate concentrations at Week 12 was predicted on a typical 60-kg woman on efavirenz (4.99%) and efavirenz with antituberculosis treatment (6.08%) when compared with medroxyprogesterone acetate alone (2.91%). This risk increased in women with higher body weight. Simulations show that re-dosing every 8 to 10 weeks circumvents the risk of subtherapeutic medroxyprogesterone acetate exposure associated with these DDIs. Dosing depot medroxyprogesterone every 8 to 10 weeks should eliminate the risk of subtherapeutic medroxyprogesterone acetate exposure caused by coadministered efavirenz and/or antituberculosis treatment, thus reducing the risk of contraceptive failure.

Emerging approaches to male contraception.

Despite significant interests in contraception by men, effective methods of male contraception are limited to vasectomy and condoms. Recently, there have been several promising advances in male contraceptive research. This review will update readers on recent research in both hormonal and nonhormonal approaches to male contraception. Hormonal approaches to male contraception have been stymied by adverse effects, formulations requiring injections or implants, a 5% to10% nonresponse rate, as well as poor understanding of user acceptability. In the last several years, research has focused on novel, orally bioavailable androgens such as dimethandrolone undecanoate and 11ß-methyl-19-nor-testosterone. Additionally, combinations of a topical testosterone gel combined with a gel containing segesterone acetate, a potent progestin, have shown promise in clinical trials recently. Simultaneously, significant preclinical progress has been made in several approaches to nonhormonal male contraceptives, including compounds that inhibit sperm motility such as eppin, compounds that inhibit retinoic acid binding or biosynthesis, and reversible approaches to obstruction of the vas deferens. It is imperative for these areas of research to continue making strides so that there is a gamut of contraceptive options for couples to choose from. Some of these approaches will hopefully reach clinical utility soon, greatly improving contraceptive choice for couples.

Vasectomy and vasectomy reversal: a comprehensive approach to the evolving spectrum of care.

Male reproduction and male contraception form an important spectrum within men's health. In this issue's Views and Reviews, four author groups detail important new developments in vasectomy clinical practice guidelines, emerging and investigational techniques in the fields of hormonal and nonhormonal male contraception, useful paradigms for patient care when deciding between sperm extraction with in vitro fertilization and vasectomy reversal, and finally, a state-of-the-art overview of recent developments in vasectomy reversal microsurgery. These articles will provide readers with a contemporary understanding of the rapidly evolving spectrum of male reproductive and contraceptive health care.

A rise in births following contraceptive failure in France between 2010 and 2016: results from the French national perinatal surveys.

BACKGROUND: In France, while the prevalence of contraception is high, a significant proportion of pregnancies are unintended. Following the 2012 pill scare, the contraceptive method mix, which was mostly comprised of pills and intrauterine devices (IUD), has become more diversified. In this changing landscape, our objective was to describe trends in live births resulting from contraceptive failure and evaluate how patterns of contraceptive use have contributed to observed changes between 2010 and 2016. METHODS: We used data from the 2010 and the 2016 French National Perinatal surveys which included all births from all maternity units in France over a one-week period. Interviews collecting information about pre-conception contraceptive practices were conducted in the maternity ward post-delivery. Women were classified as having a contraceptive failure if they discontinued contraception because they were pregnant. Our study sample included adult women who had a live birth, had ever used contraception and did not undergo infertility treatment (n = 11,590 in 2010 and n = 9703 in 2016). We evaluated changes in contraceptive failure over time using multivariate Poisson regressions to adjust for sociodemographic characteristics and pre-pregnancy contraceptive methods. RESULTS: Pre-pregnancy contraception evolved between 2010 and 2016 with a 12.3% point-drop in pill use, and conversely, 4.6%- and 3.2%-point increases in IUD and condom use, respectively. Use of other barrier or natural methods doubled between 2010 and 2016 but remained marginal (1.4% in 2010 vs 3.6% in 2016). Between 2010 and 2016, the proportion of live births resulting from contraceptive failure rose from 7.8 to 10.0%, with higher risks among younger, parous and socially disadvantaged mothers. The risk ratio of contraceptive failure in 2016 compared to 2010 remained higher after sociodemographic adjustments (aRR = 1.34; 95% CI; 1.23-1.47) and after adjusting for pre-pregnancy contraceptive method mix (aRR = 1.35; 95% CI; 1.25-1.49). Increases in contraceptive failures were concentrated among pill and condom users. CONCLUSIONS: Recent shifts in contraceptive behaviors in France following the 2012 pill scare may be associated with a subsequent increase in births resulting from short acting contraceptives failures.

Determinants of induced abortion in Tehran, Iran: the role of contraceptive failure.

OBJECTIVES: Induced abortion is highly restricted in Iran and many married women with unintended pregnancies resort to clandestine procedures, resulting in adverse health outcomes. As there is a lack of reliable data on abortion in Iran, this study aimed to examine factors predisposing women to practise abortion, factors facilitating the use of abortion and factors determining women's 'need' to use abortion to control their number of children. METHODS: The study used data from the 2014 Tehran Survey of Fertility, conducted among 3012 married women aged 15-49 years. Bivariate and multivariate binary logistic regression analyses were used. RESULTS: About 6% of women reported that they had had an abortion. The proportion was higher among women who were in their later reproductive years, women who were employed, women who intended to continue their education, women who reported a low level of religiosity, women who had two children and women who wanted no/no more children. Multivariate analysis showed that abortion was twice as high among women who had conceived their most recent birth because of the failure of a modern contraceptive method, compared with women who had discontinued or did not use a contraceptive method. CONCLUSION: The high risk of abortion among women experiencing failure of a modern contraceptive method indicates an unmet need for family planning counselling and education rather than a shortage of contraceptive methods.