Sleep (Fertility)

What is Sleep?

Sleep is a foundational biological process essential for hormonal regulation, immune function, and metabolic health — all of which directly affect reproductive potential. Chronic sleep disruption (under 7 hours per night or irregular circadian timing) is associated with disrupted LH and FSH pulsatility, reduced progesterone, impaired sperm parameters, and poorer IVF outcomes. Night shift work and circadian misalignment are specific fertility risk factors — they suppress melatonin, an antioxidant that protects oocytes and sperm during maturation.

Key facts about Sleep

• Optimal sleep for hormonal health: 7–9 hours per night with consistent sleep/wake timing
• Sleep deprivation (<6 hours/night) is associated with menstrual irregularity and anovulation in some women
• Mechanism: sleep disruption raises cortisol → suppresses GnRH → reduces LH/FSH pulsatility → impairs follicular development
• Melatonin — produced during darkness — is an antioxidant that protects oocytes and sperm from oxidative stress during maturation
• Night shift workers: 3x higher risk of menstrual disruption; associated with reduced AMH and lower IVF response in some studies
• Male sleep: short sleep duration linked to 29% lower testosterone and reduced sperm count
• Circadian disruption also impairs endometrial receptivity — melatonin receptors are present on endometrial cells
• Evidence for melatonin supplementation (3 mg at night) in IVF: some evidence for improved egg quality — not yet guideline-level

Why Sleep matters in fertility

Sleep optimisation costs nothing and has broad hormonal and oxidative stress benefits. Night shift workers should discuss their work pattern with their fertility specialist — it is clinically relevant information. For patients with poor sleep, sleep hygiene advice and treating sleep disorders (e.g., obstructive sleep apnoea — which reduces testosterone and raises oxidative stress) may improve fertility parameters before committing to treatment.

What are related terms to Sleep?