While many menstruating people notice the period bleed and the days leading up to their bleed as the most eventful and maybe even the most troublesome time of their cycle, consider this: if you're suffering from unwanted premenstrual symptoms (PMS) or irregular cycles then it's time to switch the focus to ovulation. Let's have a look at why ovulation is the most important event of the menstrual cycle, even if you are not trying to become pregnant.
Ovulation is the release of an egg from the ovary. The once per cycle event is triggered by a surge in Luteinising Hormone (LH) released from the anterior pituitary in the brain. This is an example of the brain-ovary connection aka the hypothalamic-pituitary-ovarian (HPO) axis.
7 Key facts about ovulation
The time between ovulation and menstruation is called the luteal phase.
Whether your cycle is 21 days, 28 days, 39 days, or more as can occur in conditions such as polycystic ovarian syndrome (PCOS) or hypothalamic amenorrhoea (HA), menstruation occurs 14 days after ovulation.
A short luteal phase <10-12 days is a sign of hormonal imbalance
Contraceptive hormones such as in the OCP inhibiting ovulation from occurring by interrupting the HPO axis/communication between brain and ovaries
Ovulation only occurs once per cycle
If unfertilized, an egg will live for only approximately 24 hours
The egg is the largest human cell and contains high levels of antioxidants
So what does ovulation have to do with reducing PMS and normalising irregular cycles?
After ovulation occurs a small tissue at the egg release site remains. This is called the corpus luteum and plays an integral role in having a healthy balance of sex hormones, less PMS, and overall reproductive and general health. From ovulation until just prior to menstruation the corpus luteum secretes key sex hormones including oestradiol and progesterone impact how you will feel in the days leading up to your period as well as having long-term health benefits.
Ovulation ---> Corpus luteum --> Sex hormones: oestradiol, progesterone, inhibin, relaxin.
These sex hormones stimulate the body in various ways.
Inhibin 'inhibits' the body from releasing another egg from the ovary.
Relaxin prepares body tissues for pregnancy growth, labour, and birth.
Proliferation of the endometrium (uterine lining)
Promotes healthy bone density
Promotes sex drive
Promotes healthy cervical mucous production and vaginal tissue structure
Reduces the risk of cardiovascular disease
Promotes healthy endometrial lining for egg and sperm implantation
Relaxes smooth muscle
Converts to allopregnanalone, a hormone that acts on the brain to modulate GABA activity for relaxant, neuroprotective, anti-depressant, and anxiolytic effects. Low progesterone and allopregnanolone levels are associated with major depression, anxiety disorders, premenstrual dysphoric disorder, PTSD and Alzheimer’s disease.
Plays a role in bone formation
Protects against oestrogen-driven endometrial cancer
Plays a role in thyroid function and elevated body temperature in the luteal phase
Suppresses oestrogen dominance
Missed ovulation (anovulation) in a cycle leads to a lack of natural production of progesterone and oestrodiol. This may lead to an overall low level of the two hormones, or what I see most commonly in practice which is low levels of progesterone and excess estradiol from recirculating environmental oestrogens, oestrogenic compounds, and accumulation of oestrogens from previous cycles causing a relative imbalance in these two hormones. This imbalance is what may lead to premenstrual symptoms (PMS).
Symptoms in the two weeks leading up to menstruation (luteal phase) are common but not normal and may include:
Bloating and digestive upset such as constipation or diarrhoea
Insomnia and sleep disturbance
Mood changes such as low mood, depression, irritability, anxiety
Symptoms during the period bleed may also be associated with hormonal imbalance such as excess oestrodiol but not necessarily lack of ovulation, including heavy bleeding, bleeding for more than 7 days, pain, acne, and digestive upset such as constipation or diarrhoea, and mood disturbance. Assessment to find the root cause can be done through hormone testing at the appropriate time of the cycle and/or comprehensive questioning by an experienced healthcare practitioner.