By Dr. Carla Cashin, ND | Naturopath Victoria BC
Ovulation is a key moment of the menstrual cycle, where a mature egg is released from the ovary. It is an important physiological process obviously for fertility, but plays a fundamental role in women’s health beyond this as well. For one, lack of ovulation (anovulation) can be a sign of an underlying medical condition such as polycystic ovarian syndrome (PCOS), hypothyroidism or pituitary tumor. Furthermore, without ovulation, progesterone levels are deficient. Low progesterone levels are associated with heavy menstrual bleeding and bone loss and may contribute to symptoms of PMS and perimenopause.
Who Benefits from Tracking Ovulation?
All women would benefit from learning more about their menstrual cycle and whether they are regularly ovulating, but women in the following situations may benefit most:
- If your menstrual cycles are shorter than 25 days or longer than 35 days in length, as short or long menstrual cycles are strongly associated with anovulation, and may suggest an underlying medical condition or hormonal imbalance.
- If you have heavy periods, as heavy menstrual flow can be caused by anovulation and is common in perimenopause.
- If you are having difficulty conceiving, to pinpoint whether it may be from an ovulatory issue.
How Can I Tell If I’m Ovulating?
The following tools can be used to determine if you are ovulating:
- Progesterone Levels: A blood test of progesterone levels during the luteal phase of the menstrual cycle can help identify whether ovulation occurred. This test is ideally performed 7 days before an expected period; for example, in a 28 day cycle, progesterone should be tested on Day 21. If progesterone levels are greater than or equal to 9.54 nmol/L, ovulation likely occurred.
- Basal Body Temperature Monitoring: Interestingly, progesterone has an effect on body temperature. Rising progesterone levels following ovulation will increase first morning temperatures by 0.5 F. This means you can track whether you ovulated in a particular menstrual cycle by measuring morning temperatures and looking for a temperature rise of 0.5 F that remains until the day before your period. Temperature readings need to be taken when you first wake up and before getting out of bed, since physical activity causes an elevation of body temperature as well. A mercury thermometer may be most reliable for taking basal body temperatures.
- Menstrual Cycle Charting: This involves recording the day your period starts for several months in a row to determine the length of your menstrual cycle. The first day of menstrual bleeding is Day 1 of your menstrual cycle. Menstrual cycles between 25-35 days are generally ovulatory, although recent research suggests this may not be the case. Shorter menstrual cycles may occur as the follicular phase shortens with aging, or with a short luteal phase, where progesterone levels drop sooner than they should. Cycles longer than 35 days commonly indicate that ovulation did not occur at all. It is also recommended to keep track of symptoms associated with ovulation, including breast tenderness. Breast tenderness that occurs on the upper side of the breasts near your armpits, rather than the front of the breasts, is associated with ovulation.
If I'm Having Regular Cycles, Will I Be Ovulating?
New research led by Jerilynn Prior, professor of medicine at the University of British Columbia and scientific director of The Centre for Menstrual Health and Ovulation Research, suggests even women who are having regular menstrual cycles may not be ovulating. In a cross-sectional, population based study of >3700 women, serum progesterone levels were measured to assess ovulation and it was concluded over a third of women in the study with normal cycles did not ovulate. This finding goes against common assumptions that menstrual cycles of normal length indicate ovulation. Additional evidence suggests that such “silent anovulation” in women with regular menstrual cycles is associated with diseases of older women including osteoporosis, cardiovascular disease as well as breast and endometrial cancers. It is believed one of the biggest contributors to silent ovulatory disturbances is stress, whether its physical stress such as an illness or over-exercising, nutritional stress like not eating enough calories, or mental and emotional stress, for example, a break-up with a partner or loss of a loved one. As well, adolescents who are just starting menstruation and women going through perimenopause are at risk of silent ovulatory disturbances.
For more information as well as handouts to track your menstrual cycle and ovulation, the following links from The Centre for Menstrual Health and Ovulation Research are provided:
- Prior, Jerilynn. et al. "Ovulation Prevalence In Women With Spontaneous Normal-Length Menstrual Cycles - A Population-Based Cohort from HUNT3, Norway." PLOS One. August 2015. DOI:10.1371/journal.pone.0134473
- Welt, Corrine. "Evaluation of the menstrual cycle and timing of ovulation" UpToDate. Accessed July 2017.