Sleep and fertility – is this the one factor you’ve overlooked?

We all know a good night’s sleep is important, but did you know that poor sleep can affect your fertility?

These days, lack of sleep is increasingly reported as one of the causes of unexplained infertility, and while It can be difficult to know where to start there are plenty of things you can do to improve your sleep, starting tonight!

Abnormal sleep can impact our circadian rhythm which is our internal body clock that tells us when to sleep and when to wake. Our reproductive hormones are made and secreted in conjunction with our circadian rhythm, so one cannot function without the other.  Melatonin is one of the main hormones responsible for regulating our circadian clock, so this is why the focus is on melatonin when researching and supporting the circadian rhythm.

How does melatonin work?

As night falls, our body begins to produce melatonin in response to darkness, and this signals to the brain that it’s time to do ‘night-time stuff’ like modulating blood pressure and metabolism to adjust to our bodies needs during sleep.

This is how melatonin helps us to feel sleepy at night and regulates our circadian rhythm. 

In reverse, any light – be that artificial or natural, causes that production to halt, because our brain interprets that as daytime.

If we are exposed to too much light when we should be winding down, it can impact our ability to fall asleep and therefore our sleep-wake cycle making it more difficult to achieve a restful night’s sleep.

How does melatonin affect fertility?

As well as controlling our circadian clock, melatonin is a potent antioxidant so it supports egg and sperm quality by reducing the amount of free radicals circulating that can age or damage our reproductive capacity.

But most importantly, melatonin can severely impact our fertility because it plays such a key role in the production of hormones and blood sugar balance.

Our brain uses a complex feedback system to help us make our reproductive hormones, but unfortunately our modern day 24/7 lifestyles can get in the way of this. When we feel stressed, don’t get enough sleep, or eat a diet high in processed carbohydrates, our feedback mechanisms don’t get the right signals.

For example, if we are not making enough melatonin due to lack of sleep, our brain tells our body to slow down reproductive hormones because it can sense that we aren’t able to safely reproduce.

Our melatonin levels can also affect our blood sugar balance and lead to insulin resistance, which in turn can increase or decrease the amount of testosterone and estrogen we are making, both key hormones in reproduction for men and women.

Finally, it can cause a rise in our stress hormone, cortisol, which can inhibit our ability to make the hormones we need to ovulate or make healthy sperm. In males elevated cortisol might be linked with decreased testosterone and erectile dysfunction which is likely because of the way the brain signals back to the pituitary gland to make reproductive hormones in times of stress.

This is best illustrated in research carried out on shift workers, because their routines are not in line with the typical sleep and wake pattern humans typically have.

This research shows that in males, lack of sleep is associated with lower testosterone levels, reduced sperm count and erectile dysfunction, while in women there is a connection between lack of sleep, early pregnancy loss, failed embryo implantation and ovulatory dysfunction.

What if my sleep is being disrupted due to a chronic condition?

Where you have been diagnosed with Sleep apnoea, thyroid disease, insulin resistance or a chronic condition that causes disrupted sleep the solution can be a little bit more complicated.

However, the aim here is to better understand the underlying condition and its causes so that you can treat the problem holistically.

Can’t I just supplement with melatonin?

The best way to get your melatonin is to make It yourself because ultimately this is a longer-term solution. Supplementing with melatonin can be helpful for some, but we also know that too much melatonin can impact male fertility – so it’s much safer to support your bodies production of melatonin instead.

How can you improve your melatonin production?

Sleep hygiene routine

This refers to the practice of winding down at the end of the day. Making sure that you aren’t over stimulated by bright lights, screen time or late nights and can make a restful space to encourage melatonin production.  Some ideas to include in your sleep hygiene routine include a warm shower before bed, making sure that your room is dark and not too warm and trying to stay off your devices in the hour before you want to go to sleep.

Sleep schedule

Trying to stick to a similar sleep and wake routine is helpful for setting your circadian rhythm, and over time can make getting to sleep and waking up easier. Ideally going to bed around 9:30pm and waking at 6:30am may ensure good quality sleep.

Create a dark environment for your bedroom

This can mean having blackout curtains or wearing a sleep mask. Darkness encourages melatonin production so even making sure that there are no flashing device lights or bright alarm clocks is key to signal to your brain it’s time to rest.

Avoid stimulants such as caffeine and nicotine

These two substances can make it harder for you to feel sleepy, so aiming to avoid them after 12pm (or altogether in the case of nicotine) can improve your chances of getting to sleep.  Limiting caffeine to 1-2 cups of coffee or tea a day can also help.

Limiting screen time

The blue light in our phones and computers can inhibit melatonin production, so this is key for anyone trying to conceive.

Keep your naps short

Long naps in the day can affect your ability to fall asleep at night. Instead, opt for a power nap of 20 -30 minutes if you’re feeling sleepy. If you are feeling sleepy in the day it’s helpful to understand why that might be. Blood sugar imbalances, late nights and poor nutrition can affect your energy and will address the issue at its core.

Limit shift work where possible

Shift work can affect your circadian clock because it means staying up late when its dark and your body naturally wants to make more melatonin. When this isn’t achievable, adopting a good sleep hygiene routine and setting up your environment as discussed in our sleep hygiene section can improve your sleep quality to some degree.

Eating enough of the right macronutrients to fuel your body

When we don’t eat enough calories to sustain our energy output, our brain can interpret that as a sign that we aren’t safe enough to reproduce. Implementing a balanced diet consisting of carbohydrates, protein, fruits, veggies and healthy fats is integral for supporting your ability to make reproductive hormones.

Not all carbs are created equal

If you find your energy levels dip through the day, you’re napping and then not feeling sleepy by bedtime, it might be because the type of carbohydrates you are having aren’t giving you long lasting energy.  Try sticking to low glycaemic index carbohydrates that take longer for the body to break down and use, giving you longer lasting energy through the day without draining dips in your blood glucose levels. These include brown rice, wholegrain breads, quinoa, legumes and some fruit and veg.

Manage stress

Whenever possible, it’s important to manage your stress levels. While this can often feel that it’s outside of our control, small steps like deep breathing, meditation or gratitude journaling can go a long way to supporting your nervous system. For some, yoga, reading, taking a hot bath, reducing screen time or speaking with a psychologist can be helpful to calm a busy mind.

Exercise

Gentle exercise can help regulate your blood sugar levels, decrease stress hormones and improve general well-being. However, making sure not to over exercise is just as important because this can place a strain on your body that inhibits your hormone production.

Get some early morning sunlight

Research tells us that our brain works best when exposed to early morning light to help to ‘switch off’ cortisol production in the hour after waking.  Regulating your cortisol will help to regulate melatonin because they work together via your circadian rhythm.

When it comes to preconception, its important to start planning at least 3 months but preferably 6 months prior to trying because it take 3 months to make our sperm and eggs that we are using today!

Hopefully some of these tips have resonated with you, we have many other tools at our disposal as naturopaths such as nutritional and herbal medicine so if you or someone you know is having a hard time getting sleep under control it is worthwhile speaking to a qualified Naturopath for support.

Author
Margaret Scott
Naturopath BhSc

Margaret is a degree qualified naturopath with a focus on women’s hormonal health throughout the lifespan.

Learn more about Margaret here

Book a session with Margaret here

References

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https://pubmed.ncbi.nlm.nih.gov/21872642/

https://pubmed.ncbi.nlm.nih.gov/36089592/

https://pubmed.ncbi.nlm.nih.gov/32256630/

https://link.springer.com/article/10.1007/s40675-016-0057-9