Survey study, 1987

What are the most reliable signs that ovulation has happened?

Progesterone levels are the most reliable sign. Ovulation happens about 8 hours after progesterone rises, 15 hours after LH peaks, and 24 hours after estrogen peaks. Basal body temperature and cervical mucus changes can help but are less reliable on their own.

Early or limited evidence Review article examining research on ovulation indicators, including a WHO study on ovulation timing

What they did

This was a review of research on natural methods to detect ovulation, including blood tests for hormones, ultrasound, basal body temperature, cervical mucus observation, and physical symptoms.

What they found

Progesterone rise is the strongest indicator of ovulation. WHO found ovulation occurred about 8 hours after progesterone rise, 15 hours after LH peak, and 24 hours after estrogen peak. Basal body temperature is most reliable for the infertile period before ovulation but unreliable for detecting ovulation itself. Cervical mucus changes help identify the fertile period and peak mucus correlates with ovulation. Other symptoms like cervical changes, pain, breast tenderness, and backaches are secondary signs best combined with mucus and temperature.

What it means for you

Multiple signs can help predict ovulation, but combining methods is more reliable than using one alone. This information is mainly useful for fertility planning. The main limitation is this is a review article summarizing earlier research, not a new study with original data.

8 hours

Time from progesterone rise to ovulation

15 hours

Time from LH peak to ovulation

24 hours

Time from estrogen peak to ovulation

About the study

Original title: Natural family planning indicators of ovulation
Authors: Gross BA
Journal: Clinical reproduction and fertility
Year: 1987
Study design: Survey study
What was tested: None
Read the paper: https://pubmed.ncbi.nlm.nih.gov/3322540/

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