Female Hormones – The Menstrual Cycle and Natural Contraception

Us ladies are a little more complicated than the fellas when it comes to having healthy hormones as the female hormone cycle during fertile years is geared towards reproduction. Optimal amounts of certain hormones are required at different times across the month to ensure the maturation and release of an egg occurs from the ovaries and that a pregnancy can be supported sufficiently should it take place. A number of hormones need to synchronise and a delicate balance must be maintained across the 28 days to ensure these necessary biological changes can take place.

Various glands are responsible for secreting hormones that carry out this process including the hypothalamus gland, anterior pituitary gland and the ovaries. They work together on a feedback loop increasing or decreasing the release of the major hormal players including gonadotropin releasing-hormone (GnRH), follicle stimulating hormone (FSH), luteinising hormone (LH), estrogen and progesterone. I think it’s vital women understand how their hormones work and change across the menstrual cycle as it’s incredibly useful information to have for any health goals.

The Female Hormone Axis

Slide3The female hormone cycle begins with hypothalamus gland in the brain which releases a hormone known as Gonadotropin Releasing Hormone (GnRH). This stimulates the release of two hormones known as follicle stimulating hormone (FSH) and luteinising hormones (LH) from the pituitary gland. These hormones then influence the production of estrogen and progesterone from the ovaries. The system operates on a feedback loop back to the hypothalamus and pituitary gland. Similar to a thermostat regulating the heating in your house GnRH is released partly in response to the levels of estrogen and progesterone it detects in the blood, however, other hormones like cortisol, thyroid hormones and insulin can also influence this axis which is why things like chronic stress, poor nutrition and calorie restriction can all influence the menstrual cycle, fertility and health issues associated with hormone imbalances.

Understanding The Menstrual Cycle. 

Day 1-7 (Follicular Phase)

The menstrual cycle is usually around 28-35 days in total. The onset of the menstrual bleed is considered  the first day of the cycle. During this stage the pituitary gland releases follicle stimulating hormone which stimulates the ovaries to begin ripening an egg and increase levels of estrogen.

Day 7-14
After the menstrual bleed has finished the lining of the womb begins to thicken in preparation to carry a pregnancy. Estrogen levels continue to rise and the higher levels are fed back to the brain which stops the production of follicle stimulating hormone and initiates the production of luteinising hormone which is responsible for releasing the egg (ovulation). Estrogen levels peak at around day 14, at this point a surge of luteinising hormone causes the mature egg to be released from it’s ovarian follicle (ovulation). The increased estrogen also causes the cervical mucus to thin allowing sperm to enter the womb and fallopian tubes. This initial stage in the menstrual cycle is different in every woman and can change on a monthly basis. The number of days before ovulation can range from 13 to 20 days.

Day 14-28 (Luteal Phase)
The second half of the cycle is similar for most women and lasts around 12-16 days from ovulation until the start of the next menstrual bleed. The ovarian follicle that has matured the egg ruptures and releases it into the fallopian tube and develops into something called a corpus luteum, a mini hormone gland that secretes progesterone. It remains in the ovary and the higher levels of progesterone signal to the body to maintain the lining of the womb ready to support a fertilised egg. There is a 12-24 hour window in which the egg can be fertilised by the sperm and implant itself into the lining of the womb. Higher progesterone levels cause the cervical mucus to thicken and act as a barrier to any more sperm entering the womb.

If the egg is fertilised and pregnancy occurs progesterone levels will remain high. Progesterone levels peaks around day 20 of the cycle. If the egg is not fertilised levels of progesterone and oestrogen levels will drop and in response to this the lining of the womb will eventually shed causing a menstrual bleed around day 28. The cycle then starts again from day 1.

Natural Fertility Tracking

Calendar PNG IconGiven that so many physiological changes take place across the 28-35 days it’s actually possible for you to track your cycle naturally and know which days of the month you are likely to be fertile. Knowing this information offers the most natural method of contraception as you simply abstain from sexual intercourse at this time or it can be used to help support a fertility goal. It’s also hugely empowering from a health perspective as you come to understand your body and recognise the physiological changes as they take place.  Vaginal dryness, increased mucous production, pre-menstrual symptoms and fluctuations in libido all begin to make sense when you acknowledge the changes taking place hormonally.

Tracking your cycle for this purpose is known as the “Fertility Awareness Method” or “Natural Family Planning.” It involves a combination of the rhythm method (where you use a calendar to track your cycle), monitoring changes in your basal body temperature and observing changes in your cervical mucus which alters across the month in response to the different hormone levels.

Calendar Method or Rhythm Method

When I first heard of the ‘Rhythm Method‘ years ago I thought it involved making love to a particular beat that prevented climax or pregnancy ha ha! It’s actually just referring to using a calendar to track your cycle and understanding which are your fertile days. Menstruation and ovulation may change from month to month so it is advise that you begin tracking your menstrual cycle for around 6-12 months before relying on this for contraception (use barrier methods during this time). Day 1 is the first day of you menstrual bleed.

Step 1 

Make a note of the longest and shortest cycles you observe across this time:

Shortest Cycle = 26 Days

Longest Cycle = 30 Days

Step 2

Estimate the START of the Fertility Window:

To determine the start of your fertility window you need to subtract 18 days from the length of your shortest cycle.

e.g. Shortest cycle = 26 days

26 days – 18 = 8

Fertility window starts day 8

Step 3

Estimate the END of the Fertility Window:

To determine the end of the fertility window you need to subtract 11 from the length of your longest cycle.

e.g.Longest cycle = 30 days

30 days – 11 = 8

Fertility window ends day 19

Therefore day 8-19 would be considered your fertility window as ovulation is likely to occur at some point in between these days. You cannot get pregnant on all of these days, just the 12-24 hours following ovulation.

If you wish to avoid getting pregnant you abstain from sexual intercourse or use barrier methods during the fertility window. If you wish to conceive you would increase the frequency of sexual intercourse across these days. Ideally you combine this calendar tracking with basal body temperature and observing cervical mucus to pinpoint ovulation more precisely.

Monitoring Basal Body Temperature

Monitoring basal body temperature helps identify the day you ovulate as there will be a significant increase in temperature which will remain elevated until your next menstrual bleed. It’s simple to track by keeping a thermometer on your bedside table and each morning before getting up you take your temperature orally and make a note of the result. There are digital thermometers which come with fertility charts for you to record the results on or you can use various smartphone apps.

Prior to ovulation the basal body temperature is usually around 36.1 to 36.4 degrees Celsius. The release of progesterone raises the temperature 1-2 days after ovulation by 0.1 or 0.2 degrees. The temperature will remain elevated until your next menstrual bleed. If you become pregnant it will stay elevated.

It’s important to be consistent with recording your temperatue and do it at the same time each morning. The temperature change occurs after ovulation so this method is not ideal as an indicator for conceiving as you may miss your chance to become pregnant in that cycle. However, once you have observed the pattern you will begin to know when your fertile window occurs.

NOTE: Illness, travelling, medications, sleep deprivation and alcohol can all affect your temperature too so take this into account when recording any changes.

Cervical Mucus Changes

You may have noticed that the consistency of your cervical mucus alters across the menstrual cycle. Sometimes it appears white and cloudy, other times thin and clear. There are usually 3 to 4 dry days after your menstrual cycle before the mucus start to become moist again. This increases daily for another 9 days so will likely start to notice your mucus more in your underwear, it gradually becomes clear and sticky similar to the texture of egg whites. Ovulation will usually occur within 1-2 days of the egg white mucus appearing. It’s recommended you use your fingers to collect the mucus and record it along with your temperature and cycle tracking. A more detailed overview of the mucus appearance with images can be found here.

Natural Contraception Monitors

Whilst getting to grips with monitoring your cycle naturally you might wish to employ some back up in the form of barrier methods and natural contraception monitors. Persona is a popular brand and involves using test sticks to monitor changes in luteinising hormone and estrogen in your urine. You collect your morning urine and analyse with test sticks and a hand held device. The outcome will be either a ‘Red Day’ which means there is a risk of becoming pregnant or a ‘Green Day’ where you may have intercourse without a risk of pregnancy.

In the first month of using a natural contraception monitor you have to perform 16 tests to build up a comprehensive picture of your cycle, following this you only need to test on 8 days of each cycle. Trials have shown Persona to be 94% reliable and it’s much easier if you think you will struggle to be consistent with the methods of tracking detailed above, however, it is expensive.

Contraception Choices

IMG_6506I think it’s important every woman takes some time to consider her choice of contraception. More and more studies are observing multiple side effects and long term health implications of taking the contraceptive pill or using the coil and injections. Disrupting hormone health and the natural cycle of fertility can take a long time to rebalance. A big takeaway for me when I started to look into the subject and understand the female hormone cycle was that there is only a 12-24 hour window in which you can conceive yet many women take external hormones as contraception for years and suffer negative health consequences.

After reading through information above you might be feeling a little overwhelmed but there are a number of online courses with Fertility Friend and I encourage you to read Natural Fertility by Francesca Naish and The Hormone Cure by Dr Sara Gottfried.

I personally found tracking my basal body temperature really easy and I’ve also used Persona if I know I’m travelling and busy for a while. It can be scary initially not relying upon hormonal contraception (you should always back up with barrier methods when starting out), however, this knowledge is hugely beneficial for female health generally. You can adapt your nutrition and training to reflect the hormonal changes that are taking place across the month and begin to understand the reason you may not feel like an intense gym session and perhaps need more carbs that day. You won’t beat yourself up because you didn’t feel in the mood, it might not actually be the right time for the mood 😉

A final point I’d like to make is so many female clients mention having a low libido to me. I’ve covered this in a previous blog here but again hormonal contraceptives can have a signifiant impact on this by changing the ratio of estrogen, progesterone and testosterone. Of course they are not completely to blame, stress and other factors must always be considered but if this is something you wish to resolve exploring natural contraception could be helpful.