It shocks and saddens me to know that for many women reproductive health at school involved a lesson in how not to get pregnant. The reality is, human females are only fertile for a short window each month, so perhaps more time should be dedicated to women understanding the details of their menstrual cycle and identifying deviations from the norm. I am a firm believer that the menstrual cycle is a monthly report card for female health and an indicator of broader health concerns. Until true reproductive health becomes part of the education syllabus, I’ll continue to educate women on their menstrual cycle via consultations and this blog.
The phases of the menstrual cycle
Let's start by clarifying that the female menstrual cycle begins on the first day of menstruation/period and ends on the day prior to the next period. Despite common belief, it is not simply the days of the period.
Now that we’re clear on what constitutes the cycle, let’s break the menstrual cycle down into its’ two most basic parts – the follicular phase and the luteal phase. The two phases have very distinct hormonal patterns and between them is when ovulation takes place, also known as ‘mid cycle’.
The follicular phase
Within the follicular phase is the ‘menstrual phase’ followed by the ‘pre-ovulatory phase’. The menstrual phase refers to the first five days of the menstrual cycle and is when menstruation takes place. During menstruation, the endometrium/uterine lining (containing blood, mucus, tissue fluids and epithelial cells) that had built up during the previous cycle begins to shed.
In the pre-ovulatory phase, low progesterone levels allow the pituitary gland to begin secreting another very important hormone – follicle stimulating hormone (FSH). As the name suggests, in the presence of FSH 20 – 30 follicles begin to grow towards maturity. Follicles are fluid filled sacks in the ovaries that encapsulate each egg. Eventually one of the follicles becomes ‘dominant’ and the others disintegrate while the dominant follicle continues to grow in preparation for ovulation.
Also taking place during the pre-ovulatory phase is a rise in Oestrogen, leading to a thickening of the endometrium. When this rise reaches a peak is when high levels of luteinising hormone (LH) are secreted by the pituitary gland. Ovulation (mid-cycle) usually occurs within 12 – 36 hours of this LH surge.
The luteal phase
For about two weeks following ovulation, progesterone levels go on the rise allowing the endometrium to remain thickened and conducive to the implantation of a fertilised egg. The rise in progesterone can cause body temperature to rise by as much as .2 degrees, which is why temperature can be used as a measure of ovulation having taken place. When fertilisation doesn’t take place following ovulation, progesterone levels decline which is what stimulates menstrual flow and the start of the next cycle.
An easy way to remember the sequence of hormonal influence is the mnemonic FOLOP: FSH, Oestrogen, LH, Ovulation, Progesterone.
What’s considered normal?
The stages of the cycle may differ ever so slightly month to month and they’ll certainly differ from individual to individual, so please appreciate these benchmarks for what they are – a guideline.
Duration of the cycle
A “normal” cycle is defined as 28 days with a variability of up to seven days longer or shorter. Slight monthly variations in cycle length can easily occur for a myriad of reasons, including stress, but the goal should be to maintain a level of consistency, with just a few days variance month to month considered acceptable.
Anything greater than a 35 day cycle would be defined as Oligomenorrhoea, except in the case of teenagers who’s cycles are still maturing, where a 45 day cycle would be considered normal. A shorter cycle resulting in bleeding more frequently than every 21 days would be defined as Polymenorrhoea. If the cycle is consistently less than 21 days or greater than 35 days (except in teenagers) it warrants investigation.
A period (or bleed) of less than two days warrants investigation as it may indicate an anovulatory cycle, similarly a bleed of more than seven days would be considered excessive, and the cause should be understood. Ideally the period would last for between two – seven days and appear a bright red in colour.
The colour and consistency of the period can give some clues to any abnormalities that may exist in the chorus of hormones that is the female menstrual cycle. For example, watery and/or pale bleeds can indicate a hormonal imbalance or a decline in oestrogen and/or progesterone associated with perimenopause. A heavier bleed (with the average loss being 30 – 40ml/period) could indicate high oestrogen levels, an anovulatory cycle, endometriosis or uterine fibroids, amongst other things. As could clotty bleeds. Clotts have also been associated with iron deficiency. Spotting around ovulation could be a tell-tale sign of something else requiring investigation, such as endometriosis and spotting just prior to the full first day of the cycle could be a sign of waning progesterone levels.
For the purposes of understanding the most fertile part of the cycle, especially if conception is the goal, it’s important to become familiar with when ovulation takes place and whether it has taken place. Day 14 would be considered the norm for ovulation however, there is an acceptable variance of anywhere between days 10 and 16.
It’s possible to become familiar with your norm by using detection cues, including:
1. The secretion of cervical fluids where the consistency changes to a more liquid and egg white like secretion in the 24 hours prior to ovulation.
2. A rise in temperature, where the morning temperature (basal body temperature – BBT) can be .2 degrees greater in post ovulatory phase.
3. Use LH test strips which allow the mid cycle surge in LH and therefore ovulatory phase to be detected.
Common hormonal conditions
Given the menstrual cycle is, like I said, a chorus of hormones and reliant on many instruments being in sync with one another, it’s not uncommon for things to go wrong and for variations in the above norms to take place. Some of the most common pictures of hormonal imbalance leading to dysfunction in the menstrual cycle include:
Pre-menstrual Syndrome (PMS)
PMS affects millions of Australians each year and a 1996 – 2011 meta-analysis showed that globally PMS affects 48% of women. Although it’s common, it’s not normal to experience pain, headaches, cravings and/or a distinct difference in mood or weight in the luteal phase of the cycle. These symptoms (along with many other possible cycle related symptoms) are reflective of underlying hormonal imbalances such as oestrogen excess, progesterone deficiency and/or a lack of insulin sensitivity. Through proper analysis and appropriate nutrition and lifestyle interventions the symptoms can most often be resolved.
Polycystic Ovarian Syndrome (PCOS)
The definition and diagnosis of PCOS remains controversial. The Rotterdam definition from 2003 remains the most widely accepted and states that PCOS is a hormonal condition associated with excess testosterone and lowering progesterone levels, diagnosed by having two or more of the following:
⁃ Elevated testosterone
⁃ Long cycles (35 days) or absent cycles
⁃ Polycystic ovaries as detected via ultrasound
Based on the Rotterdam Criteria 15% of women globally are affected by PCOS. As I’ll discuss in future articles, the focus for managing PCOS needs to be on addressing the underlying hormonal imbalance.
Defined as the absence of a period. Primary amenorrhea is failure of the period to commence before the age of 16. Secondary amenorrhoea is the absence of a period for three or more consecutive menstrual cycles in a female who has previously experienced cyclical menses. In most cases a lack of period is driven by stress (physiological and/or psychological), being underweight or overweight, thyroid conditions, insulin resistance, PCOS or a combination of any.
In women reaching a certain age (generally above 50, though it can happen earlier), 12 months without a period is the commonly accepted rule for diagnosing menopause. Menopause occurs when the body’s natural production of testosterone, progesterone and oestradiol is reduced due to diminishing ovarian follicles. The period of transition to a state of menopause is perimenopause, which can last anywhere up to six years. The symptoms associated with a decline in reproductive hormones can be highly debilitating, though they do vary person to person, and they are very much avoidable.
My favourite hormone balancing tools
Though each of the above hormonal conditions have a unique set of drivers, the absolute foundations of hormone balance lie in:
Achieving blood sugar control
Optimising nutrient status
Obtaining adequate sleep
Appropriately managing stress
In clinic I often carry out blood testing to understand nutrient status and thyroid function as well as salivary or urine testing to better understand the individual hormonal picture.
If you believe your cycle follows an abnormal picture and want assistance in treating root cause, please don’t hesitate to get started with me by booking in a 15 minute Complimentary Consultation. From there we can determine the next best steps for getting your cycle back on track!
Hechtman L. The Female Reproductive System. Clinical Naturopathic Medicine. 2nd ed. Elsevier; 2019:790 - 927.
ADirekvand-Moghadam, KSayehmiri, ADelpisheh, et al. Epidemiology of premenstrual syndrome (PMS) — a systematic review and meta-analysis study.J Clin Diagn Res. 2014; 8(2):106-109.
ESHRE: Consensus on women’s health aspects of polycystic ovary syndrome (PCOS).Hum Reprod. 2012. 27(1):14-24.