Have you had a sneaking suspicion that your contractions get worse at night? Maybe it feels like your pregnant body just wants to find another way to wake you up in the middle of the night. Maybe you haven’t felt them but wake up on certain days feeling like your body worked overtime while you slept. If you fall into the category of “most women”, you are probably correct – you may actually experience more contractions at night.
Research shows that contraction frequency tends to peak, on average, between the hours of 8:30-2am with the fewest contractions in the morning hours .
Contraction frequency peaks between 8:30-2am.
But why would you have more contractions while you sleep? The most likely culprit – your hormones!
Hormones = More Contractions at Night
At night, the hormones that increase the contracting nature of your uterine muscle – estrogens and prostandins – predominate . And Oxytocin and melatonin hit their peak at night too.
Melatonin is a fascinating one to consider as leader of the gang of night-time contraction-inducing hormones. The brain only releases melatonin in the dark (read: while you are sleeping). And melatonin is the buddy hormone for oxytocin – the main hormone that stimulates your uterine muscle to contract. Melatonin helps oxytocin work more efficiently to increase contraction frequency. Not only does your body produce more and more melatonin during those last few week but your body’s ability to respond to melatonin also increases as the big day approaches.
More oxytocin + more melatonin = more contractions.
Use your overnight contractions to your benefit!
It’s commonly thought that Braxton Hicks contractions help your body “warm-up” for labor.
One study has even suggested that night-time contractions kick up a notch as the big day approaches. Researchers on that study found a “nocturnal surge” in contraction frequency between 4-7am that might be predictive of labor. Women who delivered babies at term (37+ week), showed the surge pattern starting as early as 80 days before baby’s birth.
If you’re recording your contractions with Bloomlife, keep an eye on the changes to your overnight contraction counts and maybe you’ll catch your body preparing for labor! Cool, right?!
Even cooler? Join our club!
Be a part of something that could revolutionize how we think about labor and birth! The “Nocturnal Surge Club” is a group of women who are curious and want to be a part of science in action. Keep tabs on your own overnight contraction patterns (the first time anyone has seen the uterine muscle in action at night!) and work with our data science team as we decode what these patterns might mean about how the human body prepares for labor.
Postscript: Keep in mind that contractions can also increase if you are stressed or dehydrated. Try upping your water intake during the day and go easy on yourself.
 Zahn, V., and W. Hattensperger. 1993 “Circadian Rhythm of Pregnancy Contractions”. Z Geburtshilfe Perinatol. 197(1):1-10.
 Serón-Ferré M, et al. 1993. “Circadian Rhythms during Pregnancy.” Endocr Rev. 14(5):594-609.
 Sharkey, James T., Roopashri Puttaramu, R. Ann Word, and James Olcese. 2009. “Melatonin Synergizes with Oxytocin to Enhance Contractility of Human Myometrial Smooth Muscle Cells.” The Journal of Clinical Endocrinology and Metabolism 94 (2). The Endocrine Society: 421.
 Alfredo M., et al. 1993. “Relationship of Circadian Rhythms of Uterine Activity with Term and Preterm Delivery.” American Journal of Obstetrics and Gynecology 168 (4): 1271–77.