Does sleep affect your fertility?
When you are trying to conceive, it is natural to focus on the obvious things: your diet, your cycle, your supplements. Sleep, by contrast, tends to get overlooked. It is easy to dismiss a few disturbed nights as an inevitable side effect of anxiety and hope rather than something that meaningfully affects your chances of becoming pregnant.
But a growing body of research suggests that the relationship between sleep and fertility runs far deeper than most people realise, and that prioritising rest may be one of the most valuable things you can do for your reproductive health.
Today is World Sleep Day, an annual global awareness event that highlights the critical importance of sleep to our health. Here, we look at the relationship between sleep and IVF outcomes and whether better sleep could improve your fertility.
Why sleep matters for hormones and fertility
Sleep is not passive. While you rest, your body is carrying out an enormous amount of hormonal work, and many of the hormones that regulate your reproductive system are directly tied to your sleep-wake cycle.
Oestrogen, progesterone, luteinising hormone (LH), and follicle-stimulating hormone (FSH) all follow circadian rhythms, meaning they rise and fall in patterns anchored to light, darkness, and sleep. When those patterns are disrupted, our hormones can follow suit.
Central to this process is melatonin, the hormone produced by the pineal gland in response to darkness. Most of us think of melatonin simply as a sleep signal, but it plays a much broader role in female reproductive health.
Research published in Fertility and Sterility found that melatonin acts as a powerful antioxidant within the follicular fluid surrounding developing eggs, protecting oocytes from oxidative stress at the vulnerable moment of ovulation. Disrupting the regular production of melatonin through poor sleep, irregular sleep patterns, or excessive evening blue light exposure may therefore have a direct impact on egg quality.
Recent research in Frontiers in Endocrinology further highlights that disturbances to the circadian system, such as those experienced by shift workers, are associated with disrupted menstrual cycles, underscoring how tightly reproductive hormones are tied to our internal body clock.
What the research tells us about sleep and IVF outcomes
For those preparing for or undergoing IVF or ICSI treatment, the evidence around sleep is particularly compelling. A 2025 prospective cohort study published in the journal Sleep found that women reporting poor sleep quality had significantly fewer retrieved and mature oocytes compared with women who slept well. Difficulty falling asleep more than three times per week was also associated with fewer good-quality embryos. The researchers concluded that optimising sleep patterns holds real promise for improving IVF outcomes.
A separate study of women undergoing IVF or ICSI, published in Human Reproduction, found that sleeping fewer than seven hours per night was associated with reductions in both the number of eggs retrieved and their maturity.
Interestingly, the timing of sleep also appeared to matter, with mid-sleep times that were either too early or too late linked to lower fertilisation rates. The sweet spot, both studies suggest, is somewhere between seven and eight hours of good-quality, well-timed sleep each night.
Preconception planning: getting your body ready
Whether you are in the early stages of trying to conceive naturally or preparing for fertility treatment, the months before you begin are a remarkable window of opportunity. The eggs that will be retrieved or ovulated in the coming weeks and months are being matured right now, and the environment your body creates during that time matters. Sleep is one part of that picture, alongside nutrition, movement, and emotional wellbeing, but it is one that is often underestimated.
Consistent, restorative sleep supports healthy cortisol patterns, reduces systemic inflammation, and keeps the hormonal axis that governs your cycle in better balance.
Conversely, chronic sleep deprivation elevates cortisol, which can suppress GnRH and interfere with the downstream hormones that drive ovulation. You do not need to be suffering from a recognised sleep disorder for disrupted sleep to have an effect; the cumulative impact of regularly cut-short nights or poor sleep quality can quietly undermine your hormonal health over time.
Simple steps can make a real difference:
- Keeping a consistent sleep and wake time
- Reducing screen exposure in the hour before bed
- Making your bedroom cool and dark
- Limiting caffeine after midday
- Look to your diet as certain foods can either promote or inhibit sleep
- Keep fit and active
Approaching IVF in optimal health
For couples and individuals preparing for IVF, it is worth thinking about sleep as part of the broader preconception health picture rather than something separate from it.
Being in optimal health before you begin treatment does not mean being perfect. It means giving your body the best possible conditions in which to respond. For most people, that includes eating well, moving regularly, managing stress, being at a healthy weight, and yes, sleeping enough.
If you would like to explore how best to prepare for fertility treatment, arrange an appointment with one of our experts to discuss preconception planning and organise an assessment for a clearer picture of your fertility health.