How Light Exposure Affects Egg Quality and Fertility [EP 79]

If you’ve been trying to improve your egg quality, you’ve probably heard me talk about sleep. Sleep is one of the foundations I come back to again and again because it affects blood sugar, inflammation, mitochondrial health, hormone signaling, nervous system regulation, and the environment your eggs are developing in. But there’s another piece of sleep and fertility that gets far less attention: light and darkness. Your ovaries have a circadian clock, and that clock is heavily influenced by light exposure. Bright lights at night, screens in bed, and light coming through your bedroom window can all affect the signals that tell your body it’s nighttime. Darkness helps support melatonin production, and melatonin isn’t just a sleep hormone. It’s also found inside the ovarian follicles surrounding developing eggs, where it helps protect them from oxidative stress. In this episode, I’m breaking down why your ovaries care about darkness, how circadian rhythm influences reproductive health, what the research tells us about melatonin and egg quality, and five practical changes you can start making tonight. “Darkness might be one of the most overlooked tools for egg quality.” - Brooke Boskovich, MS, RD. 💡 What You'll Learn • Why your ovaries have their own circadian clock • How light exposure influences reproductive hormones and ovulation • Why darkness and melatonin matter for egg quality • How oxidative stress affects developing eggs • What research shows about sleep, circadian disruption, and IVF outcomes • Five practical ways to improve your light exposure and circadian rhythm • When melatonin supplementation may support fertility and IVF • Why egg quality depends on more than supplements alone • Why the 90 days before ovulation can be such an important window for fertility support ⏱️ Timestamps 0:46 Why darkness matters for egg quality 1:17 How light exposure affects your reproductive clock 1:47 Why your ovaries need darkness at night 2:24 Your ovaries have a circadian clock 3:04 How sleep affects fertility and ovulation 3:18 Circadian disruption, sleep, and reproductive health 4:08 Why circadian health matters before conception 4:22 Why your body needs bright light during the day and darkness at night 5:16 Melatonin and egg quality 5:39 How melatonin protects developing eggs from oxidative stress 6:18 Oxidative stress, mitochondria, and egg quality 6:48 What research says about melatonin and IVF 7:21 Can melatonin improve embryo quality? 7:37 Why melatonin supplements can't replace healthy circadian rhythms 8:06 Sleep and IVF outcomes 8:46 Sleep-disordered breathing and IVF success 9:13 Why sleep is fertility physiology 9:30 Why egg quality is about more than supplements 10:25 Five ways to support your circadian rhythm and egg quality 10:25 Get bright light early in the morning 10:51 Why consistent sleep timing matters 11:25 How to make your bedroom dark enough for better sleep 12:07 Shift work and fertility 12:30 Why the three to four months before conception matter 13:07 When melatonin supplementation may make sense 13:30 Melatonin and IVF: what the research shows 13:53 Why melatonin isn't an automatic fertility supplement 14:19 Why you can't replace darkness with a pill 14:33 What your 24-hour environment means for egg quality 15:15 Why the 90 days before ovulation matter 15:40 Simple changes you can make tonight for egg quality 16:13 Why sleep and circadian rhythm are foundational to fertility 16:29 What else should you work on before pregnancy or fertility treatment 💬 Connect & Learn More • Support the show: Please leave me a comment or review wherever you listen to this podcast • Contact me: brooke@thefertilitydietitian.health • Check out my Digital Store: https://www.thefertilitydietitian.hea... • Learn more about this episode: https://www.thefertilitydietitian.health • Subscribe on Apple Podcasts: https://apple.co/4faTvVq • Facebook:   / brookethefertilitydietitian   • Instagram:   / the.fertility.dietitian