There’s nothing better than a great night’s sleep, but the construct of our modern society doesn’t necessarily set us up for success in the sleep department. Between busy schedules, screen time, spending most of our time inside, and especially young kids (if you have them already), our sleep can really take a hit. Add into this mix a pregnancy full of changes and discomforts and getting a good night’s rest can feel like a foreign concept.
But good sleep doesn’t have to be something unattainable during pregnancy.
Getting enough good, quality sleep (especially during pregnancy) is one of the best ways to keep yourself and your baby healthy in both the short and long term.
Many studies have shown that sleep disturbances of pregnant women were associated with pre-eclampsia, gestational diabetes, preterm birth, large for gestational age, and cesarean section birth., Not to mention, disturbed sleep in pregnancy is predictive of depression and disturbed postpartum sleep – which is hard enough with a newborn! Sleep disturbances can include anything from frequent waking, obstructive sleep apnoea, restless leg syndrome, frequent urination at night, or even general discomfort.
Melatonin is the hormone in our bodies that is best known for being the “sleep hormone.” It is produced from the synthesis of tryptophan (a type of protein) from serotonin in the pineal gland of our brains. Melatonin is light-sensitive, and is released in response to darkness and inhibited in response to light. It is secreted right after the onset of darkness, peaks in the middle of the night around 2 to 4 a.m., and gradually falls as the sun rises. This on-and-off nature of melatonin establishes and informs our circadian rhythm, allowing our body to understand that when it’s daytime, it’s time to be active, and when it’s nighttime, it’s time to rest.
This rhythm is important for our sleep cycles, but it also influences a whole host of other physiological functions. There are melatonin receptors all throughout the body and our circadian rhythm influences our immune system, antioxidant defenses, and glucose regulation, too. There is some evidence that melatonin even strengthens the relationship between our core body temperature and sleep-wake rhythms.
Because there are melatonin receptors all throughout the body, you may not be surprised to learn that melatonin also influences reproduction, thanks to the melatonin receptors in our reproductive organs and systems. Preconception, melatonin modulates the production and function of luteinizing hormone and follicle-stimulating hormone – two hormones responsible for ovulation.
Throughout pregnancy, babies rely on their mothers for melatonin via transfer through the placenta. After birth, they continue to rely on mom’s melatonin via breast milk all the way up until 2-4 months after until their melatonin secretion ramps up. If you continue to breastfeed long term, your baby will continue to get melatonin through breast milk as well (milk produced at night is high in melatonin whereas daytime milk is not).
Back to pregnancy though… As you can see, the baby’s circadian rhythm is heavily impacted by its mother’s circadian rhythm. The fetal organs learn to function in a daily circadian manner based on mom’s melatonin production.
The presence of adequate melatonin also has protective effects for the fetus. Melatonin protects the embryo development, regulates and protects DNA synthesis, serves as an antioxidant, and aids in nervous system development.
When melatonin levels have been assessed during pregnancy, researchers have found that melatonin levels are higher in pregnant women during the first trimester than non-pregnant women. Melatonin levels then increase at 24 weeks and increase again at 32 weeks gestation., You can see an example of this shift in the chart below. In this study, researchers examined melatonin levels during the day and night in 30 singleton pregnant women. Look at the nighttime rise that continues to climb all the way to the 36th week.
Here are a few ways to support melatonin production during pregnancy:
Nutrition: While your pineal gland is responsible for making melatonin, you can actually get melatonin from foods, too. Melatonin can be produced from the amino acid tryptophan via serotonin. Diets rich in meat, poultry, fish, eggs, and milk, are associated with improved sleep quality, likely because these foods contain high amounts of tryptophan. In addition, cherries, nuts, pineapple, oranges, and bananas have all been found to be sources of melatonin. Turn off the lights before bed: Melatonin is inhibited by lights and is released by darkness. As your day is winding down and you prepare for sleep, dim the lights in your house to encourage the release of melatonin. You could use a salt lamp or candles. DO NOT use dimmer switches as these emit high levels of dangerous electromagnetic radiation. Change light bulbs to soft yellow or red rather than blue light. Screen time: I’m probably not the first to recommend this to you, but putting your phone, laptop, tablets, TV, etc. away at least 1-2 hours before bedtime can help bolster the rise in melatonin levels that will help you sleep. All lights suppress melatonin, but research suggests blue light is stronger at suppressing melatonin than white fluorescent lights. Sleep in a dark room: Since light exposure suppresses melatonin, you want to ensure you’re blocking out any sources of light. Remove all digital devices from the bedroom and if you must use a mobile phone as an alarm, set it onto flight-mode. Get early morning sun exposure: If you’re trying to regulate your circadian rhythm, start getting outside early in the morning, such as going for a morning walk. Exposure to sunlight during the day has been found to increase melatonin production at night, and reduce the suppressing impacts of evening light on melatonin secretion. Plus, exposure to bright lights in the morning has been found to encourage greater reduction in cortisol levels (a stress hormone) later in the day – something we want if we’re trying to relax before bed!
References – The above information is courtesy of Lily Nichols
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