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.
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Most studies start the fertile window 6 days before ovulation
A 2011 review reports that among women with normal cycles, most studies put the fertile window at six days before ovulation through the day after. Two doctors describe how hormones, mucus, temperature and ultrasound mark it.
Study at a glance, narrative review: Most studies start the fertile window six days before ovulation. Source: Murcia-Lora JM et al., 2011, DOI 10.5294/pebi.2011.15.2.3.
Key Findings
Most studies define the period of highest fertility as running from six days before ovulation through the first day after ovulation.
The human egg lives about 24 hours, so conception becomes very unlikely after the day of ovulation. Sperm can survive longer and more variably under good conditions.
In one reviewed study of 70 cycles, cervical mucus gave a longer fertile window, averaging 10.49 days, than urine hormone monitoring, which averaged 6.6 days.
A rise in basal body temperature shows that ovulation has already happened. The review says it does not predict ovulation.
The review lists a follicle that disappears or shrinks on ultrasound as the most reliable sign of ovulation, according to one cited author.
Interpretation
This narrative review comes from two clinicians, one of whom lists NaProTechnology in her practice affiliation, drawing on 77 references. The authors say the six-day window rests on normal cycles and varies between women. Stress, perimenopause, PCOS (now PMOS, polyendocrine metabolic ovarian syndrome), thyroid disease and high prolactin can disturb ovulation. The authors report that no device confirms follicle development as it happens; daily ultrasound might, and only in a clinic. The findings support further study of real-time follicle tracking in everyday clinical care.
RRM Context
Restorative reproductive medicine reads the cycle through these markers. The review credits the Creighton Model with putting temperature, mucus and cervical changes on one chart. A chart signals an ovulatory event. Serial ultrasound shows whether the follicle released an egg, so unexplained infertility with normal-looking charts is undiagnosed.
Our editorial summary of this paper, not the article's abstract.
Abstract
The purpose of this article is to review the principle concepts in literature concerning the fertile window in patients with normal menstrual cycles. The basic concepts of ovulation are examined as well. The primary emphasis is on an analysis of Brown’s theory of ovulation and a look at the basic concepts concerning secretion, the metabolism of follicle-stimulating hormones, and clinical, ultrasound and biochemical study of the follicular development of the fertile window. Also examined are the clinical biomarkers and the different endocrinal metabolites that have been tested in the fertile phase of the cycle. A number of studies are reviewed in which measured concentrations of sex steroid hormones in plasma and urine were shown to have a direct bearing on identifying the fertile period. This knowledge is relevant for different interest groups, particularly couples who are interested in fertility awareness and can benefit by applying currently available technical know-how to detect the fertile window. Couples involved in fertility regulation programs (FRP) who want to prevent pregnancy can benefit as well, as can those who want to pinpoint the most fertile time for becoming pregnant. Other target groups include persons who have no experience with FRP courses, but would like to improve their fertility awareness through a short interview, or couples who are looking for pregnancy options through NaProTechnology programs or have taken family orientation courses.
