Self-identification of the clinical fertile window and the ovulation period

Rene Ecochard, M.D., Ph.D.correspondenceemail, Olivia Duterque, M.D., Rene Leiva, M.D., Thomas Bouchard, M.D., Pilar Vigil, M.D.

Objective

To assess the sensitivity and specificity of the self-identified fertile window.

Design

Observational study.

Setting

Not applicable.

Patient(s)

A total of 107 women.

Intervention(s)

Women recorded cervical mucus observation and basal body temperature daily while undergoing daily ovarian ultrasound.

Main Outcome Measure(s)

The biological fertile window, defined as the 6 days up to and including the day of ovulation; and the 2-day ovulation window, defined as the day before and the day of ovulation.

Result(s)

The self-identification of the biological fertile window by the observation of any type of cervical mucus provides 100% sensitivity but poor specificity, yielding a clinical fertile window of 11 days. However, the identification of the biological fertile window by peak mucus (defined as clear, slippery, or stretchy mucus related to estrogen) yielded 96% sensitivity and improved specificity. The appearance of the peak mucus preceded the biological fertile window in less than 10% of the cycles. Likewise, this type of mucus identified the ovulation window with 88% sensitivity.

Conclusion(s)

These results suggest that, when perceived accurately, more accurate clinical self-detection of the fertile window can be obtained by identification of peak mucus. This may improve efforts to focus intercourse in the fertile phase for couples with fertility concerns.

Fertility and Sterility

May 2015Volume 103, Issue 5, Pages 1319–1325.e3