Overview

The growing body of research on sleep demonstrates the absolute necessity of sleep for every biological function. This includes learning, memory, brain function, mental health, appetite regulation, immune system function, metabolic function, gut microbiome health, and even cardiovascular health. It is well-established in the scientific literature that sleep is critical for all aspects of health, especially during pregnancy. Humans are the only species who will deliberately deprive themselves of sleep. The good news is you can take many evidence-based and straightforward steps to improve the quantity and quality of your sleep.

Listen Now

Article and Resources

Sleep isn’t just the key to feeling well-rested in the morning. Quality sleep will also improve your focus and productivity, reduce your stress, and overall improve your health. When you sleep, your body is in an anabolic state, which means that your body is building up things like your immune system. Immunity is vital at any life stage, but especially during your pregnancy. Sleep gives your body and your brain a chance to repair and rebuild. 

Resources for Sleep

Dr. Matt Walker is a professor of neuroscience and psychology at the University of California, Berkeley. He is also the founder and director of the Center for Human Sleep Science at Berkeley. Dr. Walker’s book, Why We Sleep, is a fantastic read. He also has a podcast with excellent information on sleep.

Dr. Andrew Huberman is a professor of neurobiology and ophthalmology at Stanford University School of Medicine. The Huberman Lab podcast is one of my favorite podcasts that explores science and science-based tools for everyday life. Dr. Huberman’s Toolkit for Sleep is an excellent recap of crucial things for sleep.

The Fundamental Importance of Sleep

There are various theories as to why humans require sleep. Some theories focus on conserving energy or inactivity as an adaptation to avoid nocturnal predators. The restorative theory proposes that sleep is necessary to repair and replete cellular components that we deplete during the day. The brain plasticity theory posits that sleep is needed for neural reorganization and the growth of the brain structure. Evidence shows that each of these theories has merit, and it is unlikely there is one key reason we have evolved to require sleep. We do know that sleep is essential.

Sleep researcher Allan Rechtschaffen said, “If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made.” On the surface, sleep seems like a disadvantage. During sleep, you cannot gather food, reproduce, socialize, and are vulnerable to predators. Every species of animal sleeps, but humans are the only species that will purposefully deprive themselves of sleep.

The growing body of research on sleep demonstrates the absolute necessity of sleep for every biological function. This includes learning, memory, brain function, mental health, appetite regulation, immune system function, metabolic function, gut microbiome health, and even cardiovascular health. It is well established in the scientific literature that sleep is a critical component for all aspects of health. This article explores the drivers of sleep, how sleep works, and evidence-based tips to improve your sleep.

The Importance of Sleep for Fertility

There is evidence that sleep modulates female hormones associated with fertility. This includes but is not limited to the thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, estradiol, progesterone, and melatonin. Your partner should also be getting sufficient quality sleep. One study found short sleep duration in men was associated with reduced fecundability (the probability of conception in a given menstrual cycle of regular unprotected intercourse). Another study found associations between sleep disturbances and semen quality. Men in the highest category of sleep disturbances had an approximately 25% lower total sperm count. If you are trying to conceive, step one is for you and your partner to prioritize sleep. Quality and sufficient sleep will improve your overall health, which increases your chances of getting pregnant.

The Importance of Sleep During Pregnancy

You can imagine the importance of sleep increases during pregnancy for both your health and your baby’s health. Surveys show sleep increases in the first trimester (on average 7.4 to 8.2 hours). In the third trimester, sleep decreases (on average 6.6 to 7.8 hours). Research links maternal sleep problems before and during pregnancy with preterm birth and child sleep problems and temperament. A study in China found poor sleep quality in the second trimester is associated with stress and depression symptoms. 

Unfortunately, there is a myriad of symptoms during pregnancy that can challenge both your quantity and quality of sleep. A separate article will examine the research on common pregnancy sleep issues and the evidence on what interventions are proven to work. This article focuses on essential tips to overall improve your sleep.

Drivers of Sleep

Two main forces drive your sleep and wake cycles, adenosine and your circadian clock. Adenosine, which aids sleep onset, passes through receptors in your brain throughout the day. When receptors pick up enough adenosine, it signals your body that you need to sleep. The other driver is your circadian clock. This is your brain’s internal 24-hour clock. When you wake up, your adrenal glands release cortisol and adrenaline (epinephrine). While we think about cortisol as the stress hormone, this hormone also helps with wakefulness. About 12-15 hours after your wakefulness trigger, your body will release melatonin from your pineal gland to help you sleep.

Sleep Cycles

Sleep falls into two categories. REM (rapid eye movement) is named for the movements your eyes make during this stage of sleep and non-REM. The non-REM sleep stage is further broken down into four stages. Stages 1-2 are stages of lighter sleep. Stages 3-4 are deeper sleep. Every sleep cycle is about 90 minutes long. You start each cycle in non-rem, then go into REM, and back into non-REM. Every sleep cycle does not have the same ratio of non-REM to REM. In the first half of the night, you get more deep sleep, and in the second half, most of your sleep cycles are REM and lighter stages of sleep. If you cut your sleep from eight to six hours, you are not just losing 25% of your sleep; you are missing out on 60-90% of your REM sleep. All stages of sleep are critical for different things.

Dial-in Your Sleep

The time from getting pregnant through the first few years of your child’s life is a massive adjustment to every aspect of your life. Adapting to new demands and schedules will have significant short-term impacts on your quality and quantity of sleep. Being a parent requires constant flexibility as you navigate caring for a baby. While you can expect less sleep, this phase will not last forever.

You should know that researchers see a baby sleeping through the night as six hours of sleep continuously. Many babies are not physically capable of sleeping even six hours, especially if you are exclusively breastfeeding. If you value your sleep, it can be stressful to think about existing on a few hours of sleep one night. Adjusting your sleep expectations can significantly affect how you feel when you don’t get enough sleep.

This article covers many tips that will improve your sleep. I encourage you to experiment with different tweaks to your diet, lifestyle, and sleep environment and utilize the tools discussed here. These tips will help you get better quality sleep during pregnancy, and you can apply these at any stage of your life.

Exercise

A systematic review suggests that sleep and exercise exert substantial positive effects on one another. Exercise will help you sleep, and quality sleep will also help you get more out of your exercise and recover better. A systematic review and meta-analysis of randomized controlled trials on the effects of exercise on sleep quality in pregnant women found that regularly exercising women had significantly enhanced sleep quality.

The American College of Obstetricians and Gynecologists recommends that pregnant women get at least 150 minutes of moderate-intensity aerobic activity weekly. They define moderate aerobic activity as one in which you move large muscles of the body in a rhythmic way enough to raise your heart rate and start sweating. If exercise is not a habit for you now, it is never too late to start. Even going for a walk in your neighborhood can benefit you, your baby, and your sleep quality.

The timing of your exercise does matter. To improve your sleep quality, you want to complete your workout at least 2-3 hours before you go to bed.

Light Exposure

Light perceived by your eyes communicates to your circadian clock. From an ancestral point of view, humans woke up with the sunrise and were exposed to sunlight throughout the day. After the sunset, there was only red and orange light from campfires. Our modern lifestyles have introduced us to artificial light that can distort our melatonin production and disrupt circadian clocks. Optimizing your light exposure is one of the biggest and easiest things you can do to improve your sleep. A large body of evidence supports exposure to blue light during the day and reducing after sunset.

Maximizing Natural Light During the Day

There are three critical times you want to view natural light during the day. The first is within 30-60 minutes after waking up; the next is around solar noon, and lastly, before sunset. You do not need to look directly at the sun; ideally, you do this without sunglasses. You may need to modify it depending on when you wake up and the weather conditions. You can do this for ten minutes on a clear day and increase the time to 20-30 minutes if cloudy or overcast. If you wake up before sunrise, you can turn on bright artificial lights in your home. Windows filter out some light, and you must view the sunshine outdoors. Consider an artificial daytime simulator if you live somewhere with little natural light.

Minimize Bright Light in the Evening

Just as you want to maximize bright and blue light during the day, you want to minimize this light at night. Unfortunately, our modern lifestyles are filled with artificial sources of blue light that we are exposed to after the sun goes down. This includes nearly every artificial light source in your home, including light bulbs, phones, computers, and televisions. Andrew Huberman recommends avoiding bright lights, especially bright overhead lights, between 10:00 p.m. and 4:00 a.m. He advises only using as much artificial lighting as necessary to remain and move about safely at night. This is because viewing bright lights of all colors is a problem for your circadian system. Candlelight and moonlight do not have the same adverse effects.

If you are a shift worker and work during the night, check out this episode of the Huberman Lab Podcast for tips to offset the adverse effects of shift work.

Tools to Reduce Blue Light

If you cannot turn your phone or computer off, the next best solution is to use a blue light blocker. Apple calls this feature called nightshift. It changes the color temperature of your screen to cut down on blue light. You can have this set automatically every day so that your phone automatically shifts to less blue light as nighttime approaches. For Android users, there are a lot of apps that perform this same function. For your computer there is a free program called that does the same thing for your computer. These solutions are less effective than turning off your screen, but they should lessen the effects.

A tool to reduce blue light from all sources in your environment is to wear blue light blocking glasses 2-3 hours before bed. My favorite is the glasses from Bon Charge because they block the specific blue and green light (400nm to 550nm) that is evidence-based to optimize melatonin production. (You can save 15% off Bon Charge with the promo code PREGNANCY.)

Light Exposure During Sleep

We examined how light exposure during awake hours can impact your sleep, but what about light when sleeping? Research demonstrates that light exposure during sleep can negatively affect your sleep quality. This study shows that ambient light during sleep can increase ocular fatigue, including eye tiredness, soreness, difficulty focusing, and vision discomfort.

Ideally, you sleep in a room that is pitch black. If you have lights coming from devices in your room, like alarm clocks or chargers, you can turn them off, face them away from you, or cover the light with a piece of tape.

Blocking outside light from entering through windows can be challenging in a neighborhood or city. One solution is to put blackout curtains in your bedroom. You can also wear a sleep mask to block out light. I use the Blackout Sleep Mask from Bon Charge. This sleep mask blocks 100% of light so you can sleep in total darkness, and is comfortable and adjustable.  (You can save 15% off Bon Charge with the promo code PREGNANCY.)

An in-depth episode on light exposure during pregnancy dives into more evidence.

Set Up a Sleep Sanctuary

Your bedroom should be a calm, relaxing environment for sleep and your sleep sanctuary. You want to train your brain that your bedroom is for sleeping and sex. That is it. Reading a book in bed, meditating, and anything else you do to relax are encouraged. Ideally, you remove anything that is a distraction from sleep. The most significant distractions are televisions, laptops, and smartphones. Not only do these emit blue light that can negatively affect your sleep, but they can also keep you awake longer.

Your sleep sanctuary may go through some changes with a new baby. The American Academy of Pediatrics has specific guidelines for safe infant sleeping and reducing the risk of SIDS (sudden infant death syndrome). The AAP recommends “infants sleep in the parents’ room, close to the parent’s bed, but on a separate surface designed for infants, ideally for the first year of life, but at least for the first six months.”

Temperature

The ideal temperature for sleeping is 65° Fahrenheit (18.3° Celsius). Your body needs to decrease the temperature by one to three degrees to fall and stay asleep. If your body temperature increases, it can cause you to wake up in the middle of the night. It will be easier to keep your room cool and use blankets you can remove if you are too warm.

You can lower your thermostat so your home and bedroom temperature is lower. Using an air conditioner fan or opening a window may also reduce the temperature of your room. Some devices for cooling your mattress, like a Chilipad, pump cool water through a mattress pad to cool your sleeping surface. I have no experience with these, and they can be expensive. You can also wear less clothing to bed or minimize blankets.

One tip for lowering your core temperature is to take a bath or shower before bed. The warm water draws blood to the surface of your skin, and when you get out of the bath, those blood vessels radiate out heat, which cools your core. You can create a similar effect by wearing socks to bed. By warming up your feet, you can lower your core temperature.

Room Temperature and Your Baby

If your baby is sharing your bedroom, you have additional considerations for the room temperature. The American Academy of Pediatrics recommends that your baby sleeps on a surface only covered by a fitted sheet with no other bedding. While you will likely have your baby in clothing to sleep, you will need to control the room’s temperature to ensure they will be comfortable. According to the AAP, infants should be dressed appropriately for the environment, with no greater than one layer more than an adult would wear to be comfortable in that environment. Unfortunately, the AAP does not recommend a specific room temperature for your baby. 

Sleep schedule 

You likely use an alarm in the morning to wake up. You may want to consider an alarm to go to sleep, too. If you have an iPhone, check out the sleep schedule feature in the Health app. Scheduling the time you go to bed makes it a great reminder to go to sleep and ensure you are setting yourself up to get enough sleep. Ideally, you go to sleep when you first start to feel sleepy. Sleep researchers have observed a naturally occurring spike in wakefulness about one hour before your natural bedtime. This can lead some people to push through that sleepy feeling and stay up too late. On the flip side, you should wake up at about the same time every day.

Having a different schedule on weekends or waking up at different times on different days can disrupt your circadian clock. In reality, this can be difficult with varying schedules and demands of work and social schedules. This is even more of a challenge, if not impossible, with a new baby. As a new parent, you will have to have flexibility. When you can control your sleep schedule, putting yourself on a schedule is best.

You are hardwired to have a natural chronotype and likely prefer waking up earlier or later. Morning larks tend to go to sleep and wake up earlier. Night owls naturally go to bed later and, as a result, sleep later in the morning. This preference is genetic, and it may be difficult to force yourself to wake up early if you naturally fall asleep later. Try different sleeping schedules and move around your 8-hour sleeping window to find what works best for you.

Develop a Bedtime Routine

Every parent will tell you about the importance of a bedtime ritual for getting their children to sleep. All of the steps you take during a bedtime routine signal your child that it is time to sleep. The same is true for adults. A bedtime routine is a way to wind down for the day and prepare for a good night’s sleep. This routine can be anything you want it to be. It could start an hour before you go to bed when you turn off your electronic devices. You may include reading, putting on pajamas, washing your face, and brushing and flossing your teeth. When you start making this a habit, this routine will trigger your brain to know it is time to sleep.

Caffeine and Alcohol

You are likely aware of the caution you should have with caffeine and alcohol during pregnancy. These substances can significantly impact your sleep, and even if you are not consuming them during pregnancy, this may be helpful in other phases of your life.

Caffeine

Adenosine, which aids sleep onset, passes through receptors in your brain throughout the day. When receptors pick up enough adenosine, it signals your body that you need to sleep. Caffeine works by blocking adenosine on receptors in your brain, which makes you feel awake despite your adenosine levels. Once your body eventually processes the caffeine (see below), all of the adenosine that was already in your system that accumulated while you were under the effects of caffeine flood in. This “caffeine crash” can make you tired quickly.

Many factors can influence how long your body breaks down and processes caffeine. This can include your genetic makeup, other medications you could be taking, weight, liver enzyme function, age, and even the altitude where you live. The time it takes your body to eliminate caffeine from your system will be different for everyone. The half-life of caffeine for adults ranges anywhere from 5-7 hours. On the short end of the spectrum, after 5 hours, your body processes 50% of the caffeine and 50% remains. After another 5 hours, you process an additional 50%, leaving 25%. This means after 10 hours, roughly 25% of the caffeine you consume is still in your system. This time is even longer for someone who does not metabolize caffeine quickly.

When you are pregnant, your body alters how it processes some drugs, like caffeine. As your pregnancy progresses, your body takes longer to process caffeine. It takes you longer to process caffeine in the second trimester than the first and even longer in the third trimester. As your pregnancy progresses and your body takes longer to metabolize caffeine, more of it passes to your baby. In addition, the half-life of caffeine in a newborn has been estimated at as high as 80 hours. After you have your baby, you will also want to be mindful of your caffeine consumption when breastfeeding because you pass it to your baby through breast milk. See this episode for the evidence on caffeine during pregnancy.

Dr. Matt Walker recommends avoiding caffeine within 12-14 hours before bed. Dr. Andrew Huberman recommends 8-10 hours. You can experiment with cutting off caffeine at different times to find what works best.

Alcohol

The American College of Obstetricians and Gynecologists strongly advises against any amount of alcohol during pregnancy. It states that there is no safe amount or type of alcohol use during pregnancy. According to the American Academy of Pediatrics, prenatal alcohol exposure can damage the developing fetus and is the leading preventable cause of congenital disabilities and intellectual and neurodevelopmental disabilities. The Academy states that during pregnancy, no amount of alcohol intake should be considered safe; there is no safe trimester to drink alcohol; all forms of alcohol, such as beer, wine, and liquor, pose similar risks; and binge drinking poses dose-related risks to the developing fetus.

Although many people feel like an alcoholic drink in the evening helps them sleep, it doesn’t. Alcohol is a sedative. It sedates your brain, which is different from natural sleep and is marked by different brain waves. There are two main ways alcohol impacts your sleep. The first is that it fragments sleep, so you wake up often. When your sleep is not continuous, it is not restorative. The second way alcohol impacts your sleep is as a powerful suppressor of REM sleep. The REM stage of sleep is critical for learning, memory, emotional processing, and brain development.

Newborn infants spend approximately two-thirds of the day asleep, about eight hours in REM sleep. There is evidence that consuming alcohol during pregnancy or while breastfeeding will negatively affect your baby’s sleep, especially REM sleep. With REM sleep being critical for brain development, you need to be cautious with alcohol.

See this episode for the evidence on alcohol during pregnancy.

Naps

Naps can help make up for some lost sleep. The length and timing of naps do matter. In a TED talk from Dr. Matt Walker, he discusses that humans are hardwired to have a drop in alertness in the afternoon, somewhere between 1:00 and 4:00 p.m. Naps can have benefits, but they can also disrupt sleep. Dr. Walker advises avoiding naps if you struggle to sleep at night. If you are not struggling with sleep and can regularly nap during the day, a short 20-minute nap earlier is fine. A nap too late in the afternoon can make it hard to fall asleep that night. Andrew Huberman Recommends limiting daytime naps to less than 90 minutes, the length of a sleep cycle, or not napping at all.

The Take-Away

If the benefits of sleep were available from a pharmaceutical drug, everyone would take it. No other intervention will improve every aspect of your health, from memory and learning to longevity. Like any practice, getting your sleep dialed in will take time. You may need to experiment and see what works best for you. This habit takes time; you cannot expect to transform your sleep habits overnight. Any effort you put into improving your sleep will be a worthwhile investment.

The time from getting pregnant through the first few years of your baby’s life is a huge adjustment. You will need to be flexible for these short phases you will be going through. This discussion continues in a separate episode. That episode will examine troubleshooting common pregnancy-related sleep issues, cover additional tools and devices, medications, and melatonin, and discuss sleep as a new parent.

Talk to Your Doctor or Midwife

If you have issues with your sleep, please discuss them with your doctor or midwife. As always, please run any medications, even over-the-counter drugs, by your care provider before taking them.

Thank you to the amazing companies that have supported this episode.