How Light Impacts Labor

Turn Down the Lights, Turn Up the Power: How Light Impacts Labor

Moms and birth professionals - today we’re diving deep into something that could transform every birthing experience: how LIGHT - yes, the simple stuff around us - can actually shape the way labor unfolds. It’s not just about ambiance, and it’s definitely not just about comfort. New research shows that the right (and wrong) kinds of light can speed up, slow down, or even pause labor. Whether you’re getting ready for your own birth or supporting growing families, this is important (especially for any moms at risk of preterm labor).

What’s the Deal With Melatonin?

Most of us think about melatonin as the “sleep” hormone. Turns out, melatonin is a superhero in labor too! Traditionally, melatonin made by the pineal gland peaks at night, helping us sleep and triggering a hormonal cascade that nudges labor into action. That’s one reason so many babies show up in those early morning hours. Oxytocin and melatonin work together really well!

But this is where it gets even more interesting: Your body is making melatonin in MORE ways than one. Recent discoveries show that the mitochondria, those powerhouse batteries inside nearly all your cells - are also busy making melatonin all day long, even when it’s bright outside. This “mitochondrial melatonin” works quietly behind the scenes, fighting off cell stress, optimizing energy, and helping labor signals do their thing all day (and night) long.

Why Light Is a Game-Changer

So, why does the color and timing of light matter so much? Because special wavelengths, especially bright blue/green (think hospital fluorescent lights) switch off your nighttime melatonin, sometimes just when your body needs it most. And here’s what happens next:

Increase in Blue/Green Light = Drop in Melatonin: Hospitals and homes filled with these LED lights after dark can slow contractions, just when the body wants to ramp up for birth.

Dim, Red, or Amber Light = Melatonin Stays High: Keeping things cozy can help your body stick to its natural, labor-supporting rhythm.

For every 10 pg/ml/h jump in nighttime melatonin, there are 1.4 - 2.1 more contractions in a half hour. Researchers observed a clear connection between higher melatonin levels and more frequent labor contractions, when melatonin increased, so did the number of contractions during the four-hour study period in both groups studied. More melatonin means those waves are coming stronger and more often, helping baby get into your arms sooner.

The Brightest New Trial: Room Light and Labor

Want to see just how hot this topic is? Right now, a cutting-edge clinical trial (“Impact of Room Light on Uterine Contractions and Labor Progression in Pregnancy”— NCT04521972) is following pregnant women from early pregnancy through birth. Their goal: to discover how different birth room lighting impacts the strength and pattern of contractions and melatonin levels.

This study is putting the spotlight (pun intended!) on how hospital and home environments can support the flow of birth hormones, all with a simple flip of a switch.

Light Therapy for Preterm Labor?

Here’s where things get futuristic. Researchers have shown that using intermittent blue or green light at night—can actually suppress melatonin and slow down contractions. Why does this matter? For moms at risk of preterm labor, popping on a pair of special light-emitting goggles might just help slow or pause labor, giving baby more time to grow.

Pioneering clinical teams (like those led by Dr. James Olcese) are exploring how targeted blue light could be a non-drug tool to delay birth and protect at-risk babies. This research is still in its early days, but the possibilities are exciting for the future of maternity care.

Skin Exposure to Light - What That Means for Labor

We’ve covered how melatonin and contractions respond to different lighting in the birth space when it enters our visual cortex, but did you know that the effects go beyond what you see? When colored light (different wavelengths), whether red, blue, or green, actually comes into contact with your skin, the body’s response can be distinctly different than what happens with ambient room light alone. Let’s look at how skin exposure to these colors can directly impact labor hormones, pain, and even the rhythm of labor itself.

Red and Near-Infrared Light: Several clinical trials found that red and near-infrared LED photobiomodulation applied directly to the skin (most commonly over the lower back or sacrum) can significantly reduce labor pain without affecting the progress or safety of labor. One study noted women who received red and infrared LED therapy reported lower pain scores, with no changes to Apgar scores or fetal wellness when compared to traditional pain control like hydrotherapy. Another study on postpartum recovery showed that infrared therapy reduced inflammation, improved healing, and promoted collagen production for scars.

• Green Light: While most clinical research on green light focuses on ambient exposure, migraine relief and its effects on melatonin (reducing contractions), skin-contact green light therapy is typically associated with calming effects and reducing redness in dermatology settings, it hasn’t been directly researched in labor as an intervention.

• Blue Light/Typical White Light in Hospitals: Though blue light has been used therapeutically for surface conditions such as neonatal jaundice and acne, prolonged exposure to blue light on the skin has demonstrated increased risk of cellular stress and dehydration in infants, and can disrupt water balance. Blue or green LED exposure to the skin has not shown consistent labor-progressing effects; the primary focus is on their inhibitory role via melatonin pathways rather than direct labor benefits (unless of course you’re in preterm labor).

• Safety of Photobiomodulation: Red light therapy applied to the skin is recognized as safe in pregnancy, with research finding no adverse maternal or fetal outcomes in both labor and postpartum studies

Compare Popular Red Light Skin Contact Devices for Pregnancy, Labor and Postpartum

What Does This Mean for You?

Whether you’re planning a birth or supporting a client, here’s how to put all this into action:

Bring red, amber, or warm, dim lights into birth spaces, especially after dark (but be careful with clients who have migraines - red may trigger one). Strangely enough it was recently discovered that green light wavelengths can reduce migraines - but let’s leave the green at home for labor.

Cut back on screen time and bright overhead lights in the evenings - swap out lightbulbs for full spectrum bulbs and use blue blocking tools/filters in the evening if you’re scrolling.

If it’s night time when you get to the hospital wear blue blocker glasses to protect your melatonin until you can get into your birth room and lower the lights. For entering or laboring in hospitals (or under any bright lights), blue-blocking glasses are a better choice than sunglasses for protecting nighttime melatonin production and supporting labor progress. If blue blockers aren’t available, very dark sunglasses are better than nothing, but they won’t be as protective against melatonin-suppressing light.

Birth professionals - share with families WHY darkness matters, melatonin is the behind-the-scenes hero and suggest blueblockers.

If there’s a risk of preterm labor, talk to your provider about emerging light-based strategies.

And remember, your body is wise, making melatonin not just from the brain, but inside your cells all the time. Every way you support your hormonal rhythms is a boost for a smoother, more empowered birth.

The birth environment matters, so flip those switches, dim those lights, and harness your body’s natural power!

Tracy

Resources

·       Rahman SA et al. “Relationship between endogenous melatonin concentrations and uterine contractions in late third trimester of human pregnancy” (Harvard/Brigham and Women's)

·       Olcese J et al. “Effects of Light and Melatonin on Contractions in Pregnant Women” (NIH Grant)

·       Clinical trial: “Impact of Room Light on Uterine Contractions and Labor Progression in Pregnancy” (NCT04521972)

·       “Pre-term labor problem: Using blue light to slow, prevent preterm labor” (ScienceDaily)

·       Reiter RJ et al. “The Melatonin–Mitochondrial Axis”

·       Voiculescu SE et al. “The Role of Melatonin in Pregnancy and the Health Benefits for the Offspring”

·       Nakamura Y et al. “Maternal Serum Melatonin Increases During Pregnancy and Falls at Delivery”