As women getting to know our menstrual cycle and how it functions both for general and fertility health allows us to build an awareness and understanding the key signs of ovulation, whether you are producing the vital fertile mucus, you are bleeding to much or too little, how regular your periods are, and knowing your fertile days.
During the cycle the rise and fall of hormones such as Oestrogen, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Gonadotropin-releasing Hormone (GnRH), Progesterone stimulate a number of complex and crucial events, mainly menstruation and ovulation.
There are three primary clues that will provide women as to when she may be ovulating:
Basal Body Temperature
Charting Basal Body Temperature (BBT)
The BBT is the body temperature on walking after at least three hours of unbroken sleep. Over the course of the cycle the follicular phase (first half of cycle) will show readings that are slightly lower than the temperature during menstruation, and another slight dip just prior to ovulation. At ovulation the BBT falls then rises (due to increased levels of Progesterone by the corpus luteum) by at least 0.2 of a degree celsius, it remains at a generally higher level than in the first half of the cycle and remains elevated until the next period. If BBT keeps rising pregnancy may have occurred.
There are many outside factors that can alter the BBT, such as:
Illness / Viral Infections
Stress - cause irregularities - extreme circumstances cessation of ovulation
Medication - changes in mucus secretions
Alcohol - direct impact on the quality of the egg
Recreational Drugs - disruption of ovarian function
Smoking - reduce blood flow - interferes with absorption of vitamins and minerals
Poor sleep patterns - may be a factor in the body's regulation of TSH / LH /FSH
Breast feeding - hormonal impalance
Overweight - changes Oestrogen levels interfering with the menstrual cycle and ovulation
Underweight - low progesterone levels - not ovulating
Shift work - alter hormone levels, not enough oestrogen - impact upon ovulation
Over exercise - can direct blood flow away from the reproductive organs
Holidays (varying climates, time change
A high temperature before ovulation may indicate an over active thyroid - a low temperature during the follicular phase may indicate an under-active thyroid.
During the first half of the cycle (follicular phase), and following the bleed - the mucus is non-fertile , thick and sticky, forming a plug over the cervix stopping semen entering. This fluid can make the vagina acidic, which can kill of sperm within a few hours.
As oestrogen (oestradiol) levels increase during the 3-4 days before ovulation the amount of fertile mucus increases and becomes clear and stretchy (egg white). Its then that the mucus turns the vaginal fluid alkaline, which help to keep the sperm alive, and provides channels (swimming lanes) that help sperm make the difficult journey through the cervix, up through the uterus and into the fallopian tubes (no satnav needed) :)
Insufficient mucus may indicate low oestrogen levels.
Some prescribed drugs may dry out, thicken or decrease mucus.
Conditions that may affect ovulation include:
Polycystic Ovary Syndrome (PCOS)
Dysmenorrhoea - painful periods
Menorrhagia - heavy periods
Amenorrhoea - absent of periods
Thyroid malfunction - under/over active
Early menopause - premature ovarian failure
Position of the Cervix
Due to changing oestrogen and progesterone levels - that cause subtle changes in the muscle and connecting tissue of the cervix, allow the position of the cervix to change throughout the cycle. For the majority of the menstrual cycle, the menstrual bleed and the relatively infertile phase the cervix is positioned low down the vagina and remains tightly closed.
In the days leading up to and preceding ovulation and the cervix gradually moves to the top of the vagina until it becomes soft, slightly open to receive sperm. After ovulation the cervix lowers again and closes, the mucus that is then produced prevents sperm from entering.
With cycles ranging from 21 to 45 days its important to know the days when there is a fertile window:
21 day cycle - ovulation may occur between days 5 - 11
25 day cycle - ovulation may occur between days 9 - 15
28 day cycle - ovulation may occur between days 12 - 18
30 day cycle - ovulation may occur between days 14 - 20
35 day cycle - ovulation may occur between days 19 - 25
40 day cycle - ovulation may occur between days 24 - 30
45 day cycle - ovulation may occur between days 29 - 35
Understanding the body's own fertility indicators gives women the opportunity to map when ovulation is most likely to occur.