El objetivo de este artículo es revisar los principales conceptos en la literatura acerca de la ventana de la fertilidad en pacientes con ciclos menstruales normales. El énfasis principal del artículo se ha dirigido al análisis de la teoría de Brown de la ovulación, revisar conceptos básicos de la ovulación, secreción y metabolismo de la hormona folículo estimulante, y al estudio clínico, ecográfico y bioquímicos del desarrollo folicular de la ventana de la fertilidad. Este artículo también repasa los biomarcadores clínicos y los diferentes metabolitos endocrinos que delimitan en la fase fértil del ciclo. Se revisan diferentes estudios en los cuales las valoraciones en suero y orina de los esteroides sexuales, han corroborado tener una correlación directa para enmarcar el período fértil. Actualmente tienen relevancia estos conocimientos en diferentes grupos de interés, sobre todo en mujeres con un alto nivel de motivación interesadas en el reconocimiento de su fertilidad, las cuales pueden beneficiarse mediante la aplicación de conocimientos técnicos actuales que detectan la ventana fértil. También estos conocimientos suelen cobrar importancia en aquellas personas que pertenecen a programas de regulación de la fertilidad (PRF), con intención de distanciar un embarazo, o de reconocer el periodo fértil del ciclo para conseguir un embarazo espontáneamente, o mediante programas de NaProTecnología. Otros grupos de interés, son aquellos en los cuales no se tiene experiencia en cursos de PRF, pero desean mejorar sus conocimientos en el reconocimiento de la fertilidad por medio de una breve entrevista, o por medio de cursos de orientación familiar.
DOI 10.5294/pebi.2011.15.2.3 10.5294/pebi.2011.15.2.3 Murcia-Lora et al. 2011, Murcia-Lora 2011
Cite this article
Murcia-Lora, J. M., & Esparza-Encina, M. L. (2011). The Fertile Window and Biomarkers: A Review and Analysis of Normal Ovulation Cycles. Persona y Bioética, 15(2), 149-165. https://doi.org/10.5294/pebi.2011.15.2.3
Murcia-Lora JM, Esparza-Encina ML. The Fertile Window and Biomarkers: A Review and Analysis of Normal Ovulation Cycles. pers.bioét.. 2011;15(2):149-165. doi:10.5294/pebi.2011.15.2.3
Murcia-Lora, José María, and María Luisa Esparza-Encina. "The Fertile Window and Biomarkers: A Review and Analysis of Normal Ovulation Cycles." Persona y Bioética, vol. 15, no. 2, 2011, pp. 149-165.
The purpose of this study was to determine the variability in length of the fertile phase of the menstrual cycle with 140 participants who produced 1,060 cycles with an electronic hormonal fertility monitor. The length of the fertile phase, as defined by the first day with a threshold level of urinary E3G and ending with a second day above a threshold of LH, varied from <1 to >7 days, with the most frequent length being 3 days.
To improve prediction of ovulation in normal cycles. Collection of women's characteristics and their menstrual cycles. Monitoring and analysis of time relationships between several indicators of ovulation: transvaginal ultrasonography, cervical mucus, basal body temperature, urinary luteinising hormone, and ratio of urinary oestrogen to progesterone metabolites. Each of eight natural family planning clinics was to study 12 women for at least three cycles. One hundred and seven normally fertile and cycling women aged 18 to 45. Daily measurements of urinary luteinising hormone, follicle stimulating hormone, oestrone-3-glucuronide and pregnanediol-3alpha-glucuronide. Basal body temperature recording and cervical mucus checking. Transvaginal ultrasound examination of the ovaries. Delays between the expected day of ovulation according to the luteinising hormone peak or to ultrasound evidence and the expected days according to the other indices of ovulation. Ultrasonography was able to show evidence of ovulation in 283 out of 326 cycles. The average time lag between luteinising hormone peak and ultrasound evidence was less than one day (+0.46) but premature and late luteinising hormone-expected date of ovulation were observed in nearly 10% and 23% of cycles, respectively. Basal body temperature rise was observed in 98% of cycles. Cervical mucus peak symptom, rapid drop in the ratio of urinary metabolites, and luteinising hormone initial rise were all close to ultrasonographic evidence in more than 72% of cycles. For accuracy and practical reasons, the cervical mucus peak symptom, the ratio of urinary metabolites and luteinising hormone initial rise might be better indices of ovulation than the luteinising hormone peak.
Arraztoa JA, 2025·J Restorative Reprod Med·
Open Access
In 1972, a seminal article was published demonstrating that women, adequately trained, could detect the approach of ovulation in the fertile window of their menstrual cycle. It was demonstrated that the symptoms perceived by women at the vulva correlate closely with changes in steroid hormone levels associated with folliculogenesis and the luteal phase. The fertility charting performed by women trained to recognize vulvar symptoms associated with hormonal changes serves as an instrument for detecting potential pathologies and monitoring the effects of treatment These findings established the biological foundations of a tool of fertility awareness tracking that has facilitated the development of restorative reproductive medicine (RRM): an approach that can be applied to identify and treat the underlying causes of infertility/subfertility.
Several core characteristics—or foundational pillars—of the RRM approach to fertility can be identified. These include: a commitment to respecting healthy physiological processes, comprehensive health care for both the couple and the potential embryo, and the provision of education and continuous support throughout the therapeutic process.
This commentary aims to elucidate the interplay of these foundational pillars by drawing upon evidence from peer-reviewed biomedical literature. Finally, the challenges faced by RRM in strengthening its scientific foundations, engaging with the broader scientific community, and promoting the dissemination of this approach are described.
This study reports on 632 cycles from 105 women who were using the CREIGHTON MODEL FertilityCare™ System to avoid pregnancy and had either a serious reason to avoid pregnancy or some degree of a lack of confidence. A progesterone level was drawn on the third day after the Peak Day as they were charting, and if the progesterone level was 2.3 ng/mL or greater, then ovulation was determined to have passed. If the level was greater than 3.0 ng/mL, this indicated that an absolute period of infertility had begun. In these cases, no pregnancies were observed. In the 27 cycles in which a specific follow-up relative to pregnancy could not be definitively determined, the progesterone levels in all cases were 2.3 ng/mL or greater with 23 of the 27 cycles being 3.1 ng/mL or greater. It is highly unlikely that any of those became pregnant as well. These cycles were collected over thirteen years (2004-2016). Two case presentations are also a part of this article of two families in which the couples had very serious reasons to avoid pregnancy. In these two couples, each of the women was multi-gravid and had no evidence of subfertility or infertility. They used the family planning progesterone level (the Peak Day +3 progesterone level) for a total of 167 cycles over a number of years successfully without a subsequent pregnancy.
This article presents a thirteen-year effort to evaluate the serum progesterone level on the third day after the Peak Day as observed by women charting the CREIGHTON MODEL FertilityCare™ System. It is known that the Peak Day is associated with ovulation, and if the progesterone reaches a certain level, then an absolute period of infertility should follow. In fact, this is what this study reflects.