RESUMO
No Brasil, a contracepção de emergência está regulamentada pelo Ministério da Saúde, desde 1996, para uso em situação de violência sexual, não uso de métodos anticoncepcionais, ou falha destes....
Assuntos
Feminino , Humanos , Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Pós-Coito/provisão & distribuição , Anticoncepção Pós-Coito/tendências , Anticoncepção Pós-Coito , Brasil , Direitos Sexuais e Reprodutivos , Política de SaúdeRESUMO
No Brasil, a contracepção de emergência foi integrada às Normas de Planejamento Familiar do Ministério da Saúde em 1996. Apesar de estar orientada a sua disponibilização para as situações de risco onde há falhas contraceptivas, falta de uso de algum método e ocorrência de estupro...
Assuntos
Feminino , Humanos , Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Pós-Coito/provisão & distribuição , Anticoncepção Pós-Coito , Anticoncepção/métodos , Brasil , Política de SaúdeRESUMO
BACKGROUND: The contraceptive efficacy of emergency contraceptive pills containing levonorgestrel (LNG-EC) has been estimated in most previous studies by judging the day of ovulation from presumptive menstrual cycle data, thus providing poorly reliable estimates. METHODS: In the present study, the efficacy of LNG-EC was determined in 393 cycles by dating ovulation on the basis of reliable hormonal and ovarian parameters validated by a database constructed in a separate study. In addition, the efficacy was determined separately for cycles in which LNG-EC was given before or after ovulation. RESULTS: For the 148 women who had sexual intercourse during the fertile days, the overall accumulated probability of pregnancy was 24.7, while altogether 8 pregnancies were observed. Thus, the overall contraceptive efficacy of LNG-EC was 68%. Among the 103 women who took LNG-EC before ovulation (days -5 to -1), 16 pregnancies were expected and no pregnancy occurred (p<.0001). Among the 45 women who took LNG-EC on the day of ovulation (day 0) or thereafter, 8 pregnancies occurred and 8.7 were expected (p=1.00). These findings are incompatible with the inhibition of implantation by LNG-EC in women. The same cases were also analyzed using the presumptive menstrual cycle data, and important discrepancies were detected between the two methods. CONCLUSION: The efficacy of LNG-EC has been overestimated in studies using presumptive menstrual cycle data. Our results confirm previous similar studies and demonstrate that LNG-EC does not prevent embryo implantation and therefore cannot be labeled as abortifacient.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Anticoncepcionais Orais Sintéticos/administração & dosagem , Anticoncepcionais Pós-Coito/administração & dosagem , Levanogestrel/administração & dosagem , Ciclo Menstrual , Ovulação , Adolescente , Adulto , Tratamento de Emergência , Feminino , Humanos , Gravidez , Resultado da Gravidez , Adulto JovemAssuntos
Humanos , Feminino , Adolescente , Adulto , Adulto Jovem , Educação de Pacientes como Assunto , Levanogestrel/administração & dosagem , Anticoncepção Pós-Coito/estatística & dados numéricos , Farmácias , Automedicação , Epidemiologia Descritiva , Anticoncepcionais Pós-Coito/administração & dosagemRESUMO
The aim of this study was to evaluate regional differences in knowledge, attitudes, and practice in emergency contraception use among Brazilian university students. A sample of university students answered a semi-structured questionnaire on knowledge, attitudes, and practice related to emergency contraception and sexual behavior. Fisher's exact test and ANOVA were used for statistical analysis. Statistical significance was set at p < 0.05. Ninety-six percent (n = 588) of the students had heard of emergency contraception, and 19% (n = 111) knew all the situations in which emergency contraception is indicated, with statistical differences between regions of the country. Forty-two percent of sexually active women in the sample had already used emergency contraception; 35% (n = 207) of students equated emergency contraception with abortion; and 81% (n = 473) thought emergency contraception involves health risks. No significant difference was observed between regions of the country regarding use and attitudes towards emergency contraception. Inter-regional differences in knowledge had no impact on students' attitudes and practice in emergency contraception. National awareness-raising campaigns are needed to improve knowledge on emergency contraception.
Assuntos
Anticoncepcionais Pós-Coito , Conhecimentos, Atitudes e Prática em Saúde , Comportamento Sexual/psicologia , Estudantes de Medicina/psicologia , Análise de Variância , Brasil , Anticoncepcionais Pós-Coito/administração & dosagem , Estudos Transversais , Feminino , Humanos , Masculino , Comportamento Sexual/estatística & dados numéricos , Estudantes de Medicina/estatística & dados numéricos , Universidades , Adulto JovemRESUMO
O objetivo deste estudo foi avaliar as diferenças regionais de conhecimento, opinião e uso de anticoncepção de emergência entre universitários brasileiros. Questionário semi-estruturado abordando conhecimento, opinião, experiência com anticoncepção de emergência e comportamento sexual foi aplicado a adolescentes de universidades brasileiras. Para análise estatística utilizou-se o teste exato de Fisher e ANOVA. Diferenças foram significantes quando o valor de p < 0,05. Cerca de 96 por cento (n = 588) dos estudantes já tinham ouvido falar sobre anticoncepção de emergência, 19 por cento (n = 111) conheciam as situações nas quais está indicada, com diferenças inter-regionais; 42 por cento das meninas que tinham vida sexual ativa já tinham feito uso do método; 35 por cento (n = 207) dos estudantes consideravam contracepção de emergência abortiva e 81 por cento (n = 473) achavam que traz riscos à saúde, sem diferença significativa entre as regiões nas questões relativas a uso e à opinião. As diferenças inter-regionais sobre conhecimento não impactaram no uso e na opinião dos adolescentes sobre anticoncepção de emergência. Programas nacionais devem ser conduzidos para melhorar o conhecimento sobre o método.
The aim of this study was to evaluate regional differences in knowledge, attitudes, and practice in emergency contraception use among Brazilian university students. A sample of university students answered a semi-structured questionnaire on knowledge, attitudes, and practice related to emergency contraception and sexual behavior. Fisher's exact test and ANOVA were used for statistical analysis. Statistical significance was set at p < 0.05. Ninety-six percent (n = 588) of the students had heard of emergency contraception, and 19 percent (n = 111) knew all the situations in which emergency contraception is indicated, with statistical differences between regions of the country. Forty-two percent of sexually active women in the sample had already used emergency contraception; 35 percent (n = 207) of students equated emergency contraception with abortion; and 81 percent (n = 473) thought emergency contraception involves health risks. No significant difference was observed between regions of the country regarding use and attitudes towards emergency contraception. Inter-regional differences in knowledge had no impact on students' attitudes and practice in emergency contraception. National awareness-raising campaigns are needed to improve knowledge on emergency contraception.
Assuntos
Feminino , Humanos , Masculino , Adulto Jovem , Anticoncepcionais Pós-Coito , Conhecimentos, Atitudes e Prática em Saúde , Comportamento Sexual/psicologia , Estudantes de Medicina/psicologia , Análise de Variância , Brasil , Estudos Transversais , Anticoncepcionais Pós-Coito/administração & dosagem , Comportamento Sexual/estatística & dados numéricos , Estudantes de Medicina/estatística & dados numéricos , Universidades , Adulto JovemRESUMO
Este artigo discute as dificuldades de implementação da Anticoncepção de Emergência (AE) nas práticas do Sistema Único de Saúde, no período de 2000 a 2008, mediante revisão crítica da literatura sobre o tema e análise de documentos oficiais. Aponta avanços no âmbito da legislação em saúde para a utilização da AE, os quais permitem oficialmente reconhecê-la no país como alternativa contraceptiva em situações emergenciais, para além dos casos de violência sexual. O levantamento da literatura nacional e internacional, centrada na América Latina e em alguns estudos da Europa, dos EUA e do Canadá, suscita questões referentes à não-incorporação dessas normas nas práticas cotidianas dos serviços de saúde, revelando representações sociais difíceis de serem revertidas em pouco tempo. Documentos oficiais do MS e do CFM foram analisados para construção do marco legal e político-institucional que pauta a discussão. Os resultados mostram paradoxos entre as normas asseguradas e as práticas existentes nos serviços de saúde: dificuldade no acesso e utilização da AE via serviços públicos de saúde; a pílula do dia seguinte (PDS) é comumente considerada abortiva por profissionais de saúde, usuárias e seus parceiros; embora pesquisas apontem aumento significativo do uso desse método, há resistência dos serviços a disponibilizá-lo; persiste a ideia recorrente no senso comum de que a AE levaria os usuários, principalmente adolescentes, a abandonar outros métodos contraceptivos de uso regular, inclusive preservativo, fato não confirmado pelos estudos realizados, pois eles indicam que os adolescentes que recorrem à AE são os que usam tal método.
This paper discusses the difficulties to implement emergency contraception (EC) in Brazilian Public Health Service, from 2000 to 2008, based on critical literature review and analysis of official documents on the theme. It shows advancements in health legislation, concerning the use of EC, that allow to recognize officially EC in Brazil as an emergency contraceptive alternative, beyond cases of sexual violence. The critical literature review - which includes data from Latin America, mainly, and some European, American, and Canadian studies - brings out issues related to the non-use of these norms by public health services in its everyday practice. This situation reveals strong social representations that are not easy to be reversed at once. Official Health Ministry and National Medical Professional Board documents were analyzed, in order to establish the legal, normative, and politicalinstitutional frameworks that guide the discussion. The analysis displays paradoxes between the established norms and the health services practices, such as: trouble accessing and using EC through public health services; health professionals and potential users commonly relate the morning after pill (MAP) to abortion; there is noticeable resistance of health services to making that method available, although researches point out substantial increase in its use; and there persists the idea that EC would lead users, especially teenagers, to abandon regular contraceptive methods, like condom - a fact not confirmed by the reviewed studies, once they show that teenagers that resort to EC are the ones that regularly use condom.
Assuntos
Humanos , Adolescente , Anticoncepção , Anticoncepcionais Pós-Coito/administração & dosagem , Serviços de Saúde , Acessibilidade aos Serviços de Saúde/tendências , Agência Nacional de Vigilância Sanitária , Serviços de Planejamento Familiar/tendências , Sistema Único de SaúdeRESUMO
BACKGROUND: Mifepristone in a dose of 10 mg is an effective emergency contraceptive when administered up to 120 hours after unprotected coitus. METHODS: Between May 2003 and February 2005, we conducted in Cuba a single-arm trial to evaluate the effectiveness of 10 mg mifepristone for emergency contraception up to 6 days after unprotected coitus. A total of 635 women who requested emergency contraception after a single act of unprotected intercourse were included in the study. RESULTS: After treatment there were 7/635 (1.1%) pregnancies (95% CI 0.4-2.3%). Pregnancy that might have occurred was prevented in 88.0% of the cases (95% CI 77.1-95.1%). The most common side effects reported by participants were fatigue (10.7%), dizziness (6.1%) and nausea (4.9%); vomiting was only reported by 0.6%. In 38/635 (6.0%) women menstruation was delayed more than 7 days. CONCLUSIONS: Mifepristone 10 mg administered is an effective emergency contraceptive with an acceptable profile of side effects up to five days, but greater studies are necessary to verify its efficacy up to 6 days after unprotected intercourse.
Assuntos
Anticoncepção Pós-Coito/métodos , Anticoncepcionais Orais Sintéticos/administração & dosagem , Anticoncepcionais Pós-Coito/administração & dosagem , Mifepristona/administração & dosagem , Adulto , Anticoncepcionais Orais Sintéticos/efeitos adversos , Anticoncepcionais Pós-Coito/efeitos adversos , Cuba , Feminino , Humanos , Menstruação/efeitos dos fármacos , Mifepristona/efeitos adversos , Gravidez/efeitos dos fármacos , Gravidez/estatística & dados numéricos , Fatores de Tempo , Resultado do TratamentoRESUMO
AIM: We examined whether the aqueous extract of Erythrina falcata, reputed to be a contraceptive in Peruvian folklore, could prevent pregnancy in the mouse. METHODS: Female mice on Day 1 of pregnancy were given aqueous extract of E. falcata or tap water (control) orally for 4 days. On Day 4 of pregnancy, animals were killed and the embryos were flushed from oviducts and uterus to examine their developmental stage, cell number, mitotic index and micronuclei frequency. Other mice were killed on Day 12 of pregnancy to determine the number of implantation sites. RESULTS: Ingestion of E. falcata diminished the percentage of embryos that progressed to blastocyst stage, reduced the cell number and mitotic index, and increased the micronuclei frequency of early embryos. The number of implantation sites was also reduced in females treated with E. falcata. CONCLUSION: The aqueous extract of E. falcata, ingested during early pregnancy, disturbs preimplantation embryo development and implantation in the mouse. These results provide the first experimental evidence of the contraceptive properties of the aqueous extract of E. falcata.
Assuntos
Anticoncepcionais Pós-Coito/farmacologia , Erythrina , Extratos Vegetais/farmacologia , Animais , Anticoncepcionais Pós-Coito/administração & dosagem , Ingestão de Alimentos , Implantação do Embrião/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Camundongos , Peru , Casca de Planta , Extratos Vegetais/administração & dosagemRESUMO
Las píldoras anticonceptivas de emergencia (PAE) han sido usadas en Chile desde los inicio de 1960. En 2001 se inician las demandas contra el Instituto de Salud Pública (ISP) por la aprobación de las PAE con sólo Levonorgestrel, por considerarlas abortivas. No pudo salir una marca, el Postinal, pero sí se aprobó con receta médica retenida el Postinor II. El juicio continúa en la Corte Suprema. El Ministerio de Salud ha tenido determinaciones contradictorias, con lo cual las mujeres usuarias del sistema público de salud están limitadas al uso de las PAE sólo en casos de violación. Aquellas mujeres que pueden comprarlas con una receta médica, las usan en casos de un coito no protegido contra el embarazo. La información científica, con mucha participación de investigadores chilenos, no ha podido demostrar que el Levonorgestrel afecte al óvulo fecundado o a su implantación en el endometrio. La anticoncepción de emergencia se ha trasformado en un debate público como tema valórico, con desinformación tanto de la población, como de los profesionales de la Salud.
Assuntos
Humanos , Feminino , Anticoncepção Pós-Coito , Anticoncepção Pós-Coito/ética , Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Pós-Coito/história , Anticoncepcionais Pós-Coito/provisão & distribuição , Chile , Levanogestrel , Saúde Pública/legislação & jurisprudência , Saúde Pública/éticaRESUMO
La anticoncepción hormonal de emergencia es aquella que actúa después de una relación sexual no protegida pero antes del embarazo. Frecuentemente se la denomina como el método de la "píldora del día después" o de "la mañana siguiente". La anticoncepción hormonal de emergencia debe realizarse dentro de las 72 horas que siguen a una relación sexual no protegida, es decir, antes de la fecundación y del inicio del embarazo. Existen varios métodos de anticoncepción hormonal de emergencias efectivos, entre los cuales los más utilizados con el de Yuzpe y el del levonorgestrel exclusivo. Estos implican solamente tomar una mayor dosis de anticonceptivos habituales por un día. Estos son verdaderos anticonceptivos que evitan el embarazo, sea inhibiendo o retrasando la ovulación. No provocan el aborto si la mujer ya está embarazada en el momento de tomar las píldoras.
Assuntos
Humanos , Feminino , Anticoncepcionais Hormonais Pós-Coito , Anticoncepcionais Hormonais Pós-Coito/provisão & distribuição , Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Femininos , Etinilestradiol/administração & dosagem , Levanogestrel/administração & dosagemRESUMO
ACIDFORM is a gel already shown to be safe in vaginal use during six consecutive days through colposcopic observation. A randomized, blinded, crossover study was carried out to compare the spermicidal effect of ACIDFORM to that of a commercial 2% nonoxynol-9 (N-9) product. Twenty sexually active, sterilized women, aged 19-45 years, with regular cycles, normal gynecological exam, no previous sexually transmitted infection (STI) and stable partner willing to undergo four postcoital tests (PCTs) at midcycle during four different menstrual cycles, were enrolled in the study. Known allergy to N-9 or ACIDFORM, oligospermic partner, chronic diseases, use of hormones, previous treatment for STI or presence of STI at screening tests were criteria for exclusion. ACIDFORM or N-9 product administered 0-30 min precoitus or ACIDFORM given 8-10 h precoitus significantly reduced the mean number of progressively motile sperm compared to control cycles (0.19, 0.07, 0.75 vs. 17.94, respectively, p<.05, Wilcoxon test). All treated cycles had five or fewer progressively motile sperm in midcycle cervical mucus, confirming in vivo the spermicidal effect of ACIDFORM previously observed in vitro and in animal models.
Assuntos
Anticoncepcionais Pós-Coito/administração & dosagem , Géis/administração & dosagem , Nonoxinol/administração & dosagem , Espermicidas/administração & dosagem , Cremes, Espumas e Géis Vaginais/administração & dosagem , Administração Intravaginal , Adulto , Soluções Tampão , Coito , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Ciclo Menstrual , Pessoa de Meia-Idade , Motilidade dos Espermatozoides/efeitos dos fármacos , Resultado do Tratamento , Esfregaço VaginalRESUMO
Previous research has established that emergency contraceptive pills are safe and have the potential to reduce unintended pregnancy; however, policy makers, providers and even women themselves have expressed concern about repeat use of the method. Evidence regarding the safety, efficacy and frequency of repeat use show that the method is safe and effective, even when used multiple times. Reported rates of repeat use are actually lower than would be expected, and needed, based on the frequency of unprotected intercourse and contraceptive failure reported in most countries. Healthcare providers should encourage use of emergency contraceptive pills as a backup after recognizable failure of barrier methods or other hormonal contraceptive methods, and should expect that women may need emergency contraceptive pills multiple times during their reproductive years.
Assuntos
Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Orais Combinados/efeitos adversos , Anticoncepcionais Pós-Coito/efeitos adversos , Feminino , HumanosRESUMO
Introduccion.La píldora postcoital ha demostrado ser razonablemente eficaz y segura, si bien su uso racional depende de que sus potenciales usuarios dispongan de información oportuna. En 1998 el conocimiento de la PPC en una muestra de adolescente de nuestra sección fue inferior al 7 por ciento. Implementamos una intervención con el propósito de incrementarlo. Objetivo: Evaluar el efecto de una intervención educacional breve sobre el estado de conocimineto de la píldora postcoital. Población, material y métodos : Adolescentes sanos mayores de 16 años que asisten a un control de salud en la Sección Medicina del Adolescente de un hospital general de comunidad. Intervención : Provisión de información ( 10 minutos aproximadamente ) sobre la píldora poscoital ( método de Yuzpe ). Diseño : Comparación de las encuestas de dos cortes transversales antes y 30 meses después de comenzada la intervención. Se trabajó con dos muestras de conveniencia, no probabilísticas. Basal:151 individuos y "expuesta": 93. Se consignó : edad, sexo, actividad sexual, método anticonceptivo y conocimiento de la píldora postcoital. Resultado principal : Proporción de adolescente que conocía la PPC y odds ratio (OR) de conocimiento de la píldora poscoital basal y luego de 30 meses de comenzada la intervención. Resultados : Edad (mediana años): basal 18 vs expuestos 19. Mann-Whitney: (p=0,04). Sexo : Mujeres basal 54 por ciento contra expuestos 62 por ciento ; NS. Sexualmente activos/as: basal 60 por ciento contra expuestos 72 por ciento; NS. Método anticonceptivo : Sin diferencias entre los grupos. Proporción de adolescentes que conocían la píldora poscoital: Basal 7 por ciento contra expuestos 53 por ciento. OR(IC 95 por ciento) = 15,7 (7,4-33,1) ; (p<0,0001). Análisis multivariable : Se controló el efecto de las siguientes variables de confisión: edad, actividad sexual, uso exclusivo de preservativos.El OR ajustado (CI95 por ciento) fue de 17.9 (7,9-40,4) (p<0,0001). Conclusiones :1) En el grupo expuesto hubo un considerable aumento en las probabilidades de conocer la píldora poscoital.2) Estos hallazgos no deben interpretarse como consecuencia exclusiva de la intervención. 3) Serán necesarios nuevos estudios para demostrar si el mayor estado de conocimiento de la píldora poscoital se traducirá en una reducción de la taza de embarazos no planificados en adolescentes, si la intervención es efectiva en otro tipo de población, y si su efecto persiste en el tiempo.[AU]
Assuntos
Adolescente , Anticoncepcionais Pós-Coito/administração & dosagem , Educação Sexual , Gravidez na Adolescência/prevenção & controle , Gravidez não DesejadaRESUMO
Levonorgestrel (LNG), a progestin widely used for regular hormonal contraception, is also used for emergency contraception (EC) to prevent pregnancy after unprotected intercourse. However, its mode of action in EC is only partially understood. One unresolved question is whether or not EC prevents pregnancy by interfering with postfertilization events. Here, we report the effects of acute treatment with LNG upon ovulation, fertilization and implantation in the rat. LNG inhibited ovulation totally or partially, depending on the timing of treatment and/or total dose administered, whereas it had no effect on fertilization or implantation when it was administered shortly before or after mating, or before implantation. It is concluded that acute postcoital administration of LNG at doses several-fold higher than those used for EC in women, which are able to inhibit ovulation, had no postfertilization effect that impairs fertility in the rat.
Assuntos
Anticoncepcionais Pós-Coito/farmacologia , Fertilização/efeitos dos fármacos , Levanogestrel/farmacologia , Congêneres da Progesterona/farmacologia , Animais , Anticoncepcionais Pós-Coito/administração & dosagem , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Injeções Subcutâneas , Levanogestrel/administração & dosagem , Masculino , Congêneres da Progesterona/administração & dosagem , Ratos , Ratos Sprague-DawleyRESUMO
Emergency contraception is used to prevent pregnancy after unprotected sex but before pregnancy begins. Currently, women can use emergency contraception by taking higher doses of the active ingredients found in ordinary oral contraceptive pills [either combined estrogen-progestogen (progestin) or progestogen-only formulations], or by having providers insert copper-bearing intrauterine devices (IUDs). The antiprogestogen mifepristone also has an excellent efficacy and safety profile as emergency contraception, but it is currently available for this indication only in China. Many studies have documented providers' and women's fears about the individual and public health safety risks of emergency contraception. Some of these concerns include potentially increased risks of cardiovascular events (including arterial and venous disease), worries about possible effects on future fertility, feared teratogenic consequences following method failure or inadvertent use during pregnancy, exaggerated or extreme fears of adverse tolerability, and concerns about drug interactions with other medications. Wider public health questions include feared reductions in the use of ongoing, more effective contraception, possible 'abuse' of emergency contraception through overly frequent use, and potential increases in risky sexual encounters (owing to the existence of a back-up, postcoital method) and therefore in rates of sexually transmitted infections, including HIV/AIDS. These fears can each be generally allayed. Direct and indirect investigations of emergency contraception in the biomedical and social science literature, the extensively documented safety profile of ordinary oral contraceptives, and more than 30 years of clinical experience since hormonal emergency contraception was first described, give strong evidence for its safety. This review confirms declarations by the World Health Organization and the US Food and Drug Administration, and shows that emergency contraception has an excellent safety profile in nearly all women. Finally, emergency contraception allows women a second chance to avoid unwanted pregnancies. Whether pregnancy is carried to term or terminated, the condition has inherent risks that are greater than any posed by emergency contraception.
Assuntos
Anticoncepcionais Pós-Coito/administração & dosagem , Anticoncepcionais Pós-Coito/efeitos adversos , Dispositivos Intrauterinos de Cobre/efeitos adversos , Anormalidades Congênitas/etiologia , Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Orais Combinados/efeitos adversos , Esquema de Medicação , Interações Medicamentosas , Estrogênios/administração & dosagem , Estrogênios/efeitos adversos , Feminino , Fertilidade , Humanos , Mifepristona/administração & dosagem , Mifepristona/efeitos adversos , Gravidez , Progestinas/administração & dosagem , Progestinas/efeitos adversos , Saúde Pública , Medição de Risco , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/etiologia , Estados Unidos , United States Food and Drug Administration , Organização Mundial da SaúdeRESUMO
The effects of short-term administration of levonorgestrel (LNG) at different stages of the ovarian cycle on the pituitary-ovarian axis, corpus luteum function, and endometrium were investigated. Forty-five surgically sterilized women were studied during two menstrual cycles. In the second cycle, each women received two doses of 0.75 mg LNG taken 12 h apart on day 10 of the cycle (Group A), at the time of serum luteinizing hormone (LH) surge (Group B), 48 h after positive detection of urinary LH (Group C), or late follicular phase (Group D). In both cycles, transvaginal ultrasound and serum LH were performed from the detection of urinary LH until ovulation. Serum estradiol (E2) and progesterone (P(4)) were measured during the complete luteal phase. In addition, an endometrial biopsy was taken at day LH + 9. Eighty percent of participants in Group A were anovulatory, the remaining (three participants) presented significant shortness of the luteal phase with notably lower luteal P4 serum concentrations. In Groups B and C, no significant differences on either cycle length or luteal P4 and E2 serum concentrations were observed between the untreated and treated cycles. Participants in Group D had normal cycle length but significantly lower luteal P4 serum concentrations. Endometrial histology was normal in all ovulatory-treated cycles. It is suggested that interference of LNG with the mechanisms initiating the LH preovulatory surge depends on the stage of follicle development. Thus, anovulation results from disrupting the normal development and/or the hormonal activity of the growing follicle only when LNG is given preovulatory. In addition, peri- and post-ovulatory administration of LNG did not impair corpus luteum function or endometrial morphology.