How Pregnancy Impacts Sleep and the Onset of Gestational OSA 

We’ve all heard the expression, “You’re eating for two”, which means that a woman diet during pregnancy should improve in quality, not just quantity. (Pregnant women typically only need around 300 extra calories per day.)   

But how about the expression, “Sleeping for two”?  How much sleep do pregnant women need through each trimester? How is sleep quality affected during pregnancy? And what are common complaints pregnant women have about the challenges of a good night’s sleep? 

Why is Sleep Essential During Pregnancy? 

“Pregnancy is a very special and joyous time in a woman’s life, but it is also a time of serious sleep disturbances. Most epidemiologic studies suggest there is an increased need for sleep during pregnancy. The high levels of human chorionic gonadotropin and progesterone that are required to maintain pregnancy are also soporific and thermogenic, promoting daytime sleepiness and early sleep onset.  Meanwhile, there is growing evidence linking sleep disturbances with adverse pregnancy outcomes. The message is clear: good sleep is important for a healthy pregnancy.” – Christine H.J. Won, MD, MS; Sleeping for Two: The Great Paradox of Sleep in Pregnancy, JCSM study 

1. HORMONAL CHANGES 

As the JCSM study above mentioned, higher levels of hormones including progesterone and hCG impact the need for sleep. How?

“During first trimester, a rise in progesterone levels may cause excessive day time sleepiness, decreased muscle tone, increased risk of sleep apnea, snoring and sleep interruptions. In animal studies, progesterone administration has been observed to have sedating effects, to reduce wakefulness, shorten the latency and increase the duration of non-rapid eye movement (NREM) sleep.” – NIH study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017073/)

Progesterone is a hormone essential for maintaining pregnancy which increases significantly during the first trimester, has a sedative effect that can make pregnant women feel more tired. Progesterone is a hormone that plays a vital role in pregnancy by thickening the uterine lining, preventing ovulation throughout pregnancy, preventing preterm labor by suppressing uterine contractions, and preparing the mammary glands for breastfeeding.

“HCG increases immunoreactive PGD2 and decreases PGE2 in the brain areas that control sleep and activity.” – NIH study (https://pubmed.ncbi.nlm.nih.gov/11394199/)

Human chorionic gonadotropin (hCG) is a hormone that plays a vital role in pregnancy by thickening the uterine lining to support the growing embryo; stimulating progesterone production which helps prepare the uterine lining for implantation; tells the body to stop menstruation; supports implantation of the baby; and stimulating the thyroid gland. hCG levels rise after conception and continue to rise until about 10 weeks in pregnancy.

2. PHYSICAL DEMANDS 

A woman’s body is working overtime to nurture, feed and grow a healthy baby, so restorative and abundant quality sleep is a main ingredient to give the pregnant body the rest it needs.  A growing baby requires more energy from the mother’s body, as it works to support the baby, the mother’s metabolism speeds up, increasing the need for rest and recovery. Blood volume and heart rate increase as well, which can contribute to physical fatigue. 

3. EMOTIONAL DEMANDS 

It goes without saying that the emotional and psychological changes can affect sleep. Even though, becoming a mother or adding another child to the family is an exciting and joyous prospect, there is much for a pregnant women to worry about: the health of the child, a safe and easy delivery, the monetary cost of adding a child to the family including childcare, the prospect of many sleepless nights ahead, potty training, college funds … the list goes on.   

So, it’s no surprise that pregnancy can also bring about heightened emotions, stress, and anxiety, which can affect sleep quality.  The heavy load of mental fatigue may increase the need for rest to cope with emotional demands. And on the flipside, less sleep may increase symptoms of anxiety and depression, which can only exacerbate the emotional changes pregnancy induces. 

4. IMMUNE SYSTEM DEMANDS 

Pregnancy temporarily suppresses parts of the immune system to prevent the body from rejecting the fetus. Natural killer cells and neutrophils are more active, T-cell active increases, and there is an increase in immune tolerance, all to protect the mother and fetus from illness, infections, and pneumonia. 

How Much Sleep does a Pregnant Woman Need? 

Pregnant women generally need more sleep than they normally would, yet the recommended amount of sleep during pregnancy is about 7 to 9 hours per night, which is similar to non-pregnant adults. However, many pregnant women may find that they need more than this, particularly in the first and third trimesters due to increased fatigue. Let’s break it down by trimester: 

1. First Trimester: Fatigue can be intense due to rising progesterone levels, so many women feel the need to sleep more. Some women may benefit from naps during the day to offset nighttime sleep disturbances. 
2. Second Trimester: Sleep may improve somewhat during this phase, and women may feel more energetic. However, maintaining 7-9 hours is still important for overall health. 
3. Third Trimester: Sleep may become more disrupted due to physical discomforts, such as a growing belly, leg cramps, and frequent urination. Extra rest during the day, including naps, can help compensate for the lack of sleep at night. 

Some recommend pregnant women should aim to get 8 to 10 hours of sleep per night. However, the amount of sleep a pregnant woman needs can vary depending on her individual health and habits.  

Each trimester of pregnancy can affect sleep differently, with women often feeling more tired in the first and third trimesters. Listening to the body and resting as needed is crucial during pregnancy, because poor sleep during pregnancy can have several potential risks and negative effects, both for the mother and the developing baby.  

What Risks are Incurred from Poor Sleep During Pregnancy? 

“However, pregnant women experience less sleep, increased wakefulness, and excessive daytime sleepiness compared to non-pregnant populations, with 80% of women reporting poor sleep throughout pregnancy. Poor sleep during pregnancy is associated with an increased risk of adverse maternal and fetal health outcomes including preeclampsia, gestational diabetes mellitus, caesarean delivery, and preterm birth as well as general tiredness, fatigue, and cognitive impairment. The need for non-pharmacological approaches to improve poor sleep during pregnancy has been established due to the safety risks posed by pharmacological methods.” – NIH study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944079/) 

Here are some risks associated with inadequate or poor-quality sleep during pregnancy: 

• Increased Risk of Gestational Diabetes: Lack of sleep can affect insulin regulation and glucose metabolism, increasing the risk of developing gestational diabetes. 
• High Blood Pressure and Preeclampsia: Sleep deprivation and sleep disorders like sleep apnea, are associated with an increased risk of hypertension and preeclampsia. 
• Preterm Birth: Poor sleep has been linked to an increased risk of preterm birth (delivery before 37 weeks).
• Increased Risk of Cesarean Delivery: Some research suggests that women who have chronic sleep problems during pregnancy may be more likely to require a C-section during delivery.  
• Prolonged Labor and Birth Complications: Lack of sleep can interfere with a woman’s ability to cope with labor, resulting in longer labors, an increase of needing interventions like epidurals or assisted deliveries. 
• Depression and Anxiety: Pregnant women who don’t get enough sleep are at higher risk for prenatal and postpartum depression.  
• Low Birth Weight: Poor sleep during pregnancy has been associated with a higher likelihood of low birth weight, causing complications for the infant. 
• Impaired Cognitive Function: Pregnant women may find it harder to concentrate and may experience “pregnancy brain,” or forgetfulness, more severely. 

What are Common Complaints that Affect Sleep During Pregnancy? 

As pregnancy progresses, physical discomforts like back pain, frequent urination, leg cramps, and heartburn can disrupt sleep patterns. These discomforts often make women more tired during the day, requiring additional sleep. 

“A US National Sleep Foundation’s Women and Sleep Survey in 1998 found 78% of women reported disturbed sleep during pregnancy and 15% of women developed Restless Legs Syndrome (RLS) during 3^rd trimester of pregnancy.” – NIH study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017073/) 

There are many factors that can affect the quality of sleep during pregnancy, let’s discuss the most common: 

• Frequent Urination:  As the uterus grows, it puts pressure on the bladder, especially during the third trimester, leading to frequent trips to the bathroom throughout the night.  
• Back Pain and General Discomfort: The growing belly, weight gain, and changes in posture can cause back pain and discomfort, particularly in the second and third trimesters.  
• Gastroesophageal reflux disorder (GERD): Hormonal changes during pregnancy relax the valve between the stomach and esophagus, which can result in acid reflux or heartburn, especially when lying down. GERD can affect up to half of pregnant women in the third trimester.  
• Restless legs syndrome (RLS): Most common in the third trimester, RLS causes an irresistible urge to move the legs or leg cramps, often accompanied by uncomfortable sensations.  
• Insomnia: Affecting up to 80% of pregnant women, insomnia can result from a combination of physical discomfort, anxiety, hormonal changes, and frequent waking. 
• Vivid Dreams and Nightmares: Pregnant women often report waking up from intense dreams and having trouble falling back asleep. 
• Difficulty Finding a Comfortable Sleeping Position: Particularly in the third trimester, sleeping on the back becomes less comfortable and not recommended, as it can compress the vena cava (a major blood vessel), reducing blood flow.  

Sleep Disordered Breathing (SDB) & Pregnancy 

“The physiologic changes of pregnancy can produce or worsen SDB; up to a third of pregnant women report snoring in the third trimester.” – NIH study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6733415/ )

Another pregnancy-induced respiratory change that can impact sleep is Sleep Disordered Breathing (SDB) which causes breathing changes during sleep, including snoring, gasping, snorting, and apneas.  And many women complain about shortness of breath which is caused when the uterus expands, it can press against the diaphragm, making it harder to breathe deeply, especially when lying flat. A more serious breathing condition that can affect pregnancy is Obstructive Sleep Apnea (OSA). 

Obstructive Sleep Apnea (OSA) & Pregnancy 

“There are likely 2 distinct clinical phenotypes of OSA in pregnancy: women with preexisting OSA who become pregnant and may experience worsening of the condition (chronic OSA complicated by pregnancy); and women who develop OSA related to weight gain and airway/respiratory changes of pregnancy or hypertensive disorders of pregnancy (HDP) (gestational OSA). There is some evidence that the latter condition may improve or resolve entirely after pregnancy.” – NIH study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6733415/) 

Obstructive sleep apnea (OSA) can develop or worsen during pregnancy, and is a risk factor for hypertensive disorders, gestational diabetes, and severe maternal morbidity. There are two types of OSA that can occur during pregnancy: 

• Chronic OSA: Women who already have OSA and become pregnant 
• Gestational OSA: Women who develop OSA during pregnancy 

OSA is a blockage in the upper airway that causes breathing to stop during sleep, which becomes more serious during pregnancy because it can also reduce oxygen flow to the fetus. The causes of OSA especially during pregnancy can be attributed to weight gain, hormonal fluctuations, the growing fetus putting pressure on the respiratory system, and the enlarging uterus elevating the diaphragm.  

OSA is a common but yet often under-diagnosed sleep disorder that can occur during pregnancy. Its imperative to catch it early, optimally in the first or second trimester, to avoid serious complications, which are discussed above, that can negatively impact the health of the mother and child. Here are some common symptoms of OSA to look out for: 

• Daytime sleepiness 
• Loud snoring 
• Waking up gasping or choking 
• Insomnia 
• Lack of concentration 
• Cognitive deficits 
• Mood changes 
• Morning headaches  

Early diagnosis and effective treatment can significantly improve outcomes. Managing OSA during pregnancy involves a combination of lifestyle changes, medical interventions, and careful monitoring by a sleep physician.  Because the temporary cessation of breathing during sleep due to airway obstruction, can increase the risk of complications such as gestational diabetes, hypertension, and preeclampsia, it’s imperative to take a responsive approach. 

OSA can be managed with a number of treatments, including:  

1. Continuous Positive Airway Pressure (CPAP) Therapy: CPAP is considered safe for pregnant women and can significantly reduce OSA symptoms, improving both sleep quality and oxygen levels. 
2. Positional Therapy: Pregnant women with OSA are encouraged to sleep on their side, particularly the left side, to improve breathing. Special pregnancy pillows can help maintain a side-sleeping position throughout the night. Sleeping with the head elevated can help reduce airway obstruction and improve breathing during sleep. A wedge pillow can keep the airway more open and reduce apnea episodes. 
3. Weight Management: Since weight gain during pregnancy can exacerbate OSA, managing it through a healthy diet and exercise (with approval from a healthcare provider) can help reduce OSA severity.  
4. Nasal Congestion Relief: Nasal congestion due to hormonal changes can be treated using nasal strips, saline nasal sprays, or humidifiers may help open nasal passages, making it easier to breathe during sleep.  

Managing conditions like gestational diabetes and hypertension, through regular prenatal care, monitoring, and treatment can help reduce the overall impact of OSA on the pregnancy. It’s important for pregnant women with OSA to be closely monitored by their healthcare team, including a sleep physician, to prevent complications. 

Contact Everything Sleep Idaho if you are pregnant or considering becoming pregnant. Our team of sleep physicians, sleep technologists and respiratory therapist can ensure continued sleep health throughout all three trimesters, postnatally and throughout your life. As Idaho’s sleep center, we play a crucial role in helping individuals address sleep disorders and improve their overall sleep quality.