When to stop sleeping on back pregnancy is a critical consideration for expectant mothers, demanding a thorough understanding of the physiological changes occurring during gestation. Pregnancy introduces a myriad of transformations, impacting everything from blood circulation to hormonal influences. These alterations necessitate careful attention to sleeping positions, as they can significantly affect both maternal and fetal well-being. This discussion delves into the intricacies of safe sleep practices, aiming to provide clarity and guidance throughout the journey of pregnancy.
The supine position, or sleeping on the back, poses specific challenges. As the uterus expands, it can compress the inferior vena cava, potentially restricting blood flow to both the mother and the developing fetus. Furthermore, hormonal shifts, such as increased progesterone levels, influence muscle relaxation, which may impact sleep posture. The information provided here aims to illuminate the risks associated with certain sleeping positions, while advocating for safer alternatives to ensure optimal health outcomes.
Physiological Changes During Pregnancy Affecting Sleep Position
During pregnancy, a woman’s body undergoes numerous physiological adaptations to support the developing fetus. These changes significantly impact various bodily functions, including the cardiovascular and musculoskeletal systems, influencing the optimal sleep position. Understanding these alterations is crucial for ensuring both maternal and fetal well-being.
Impact of Increased Blood Volume on Maternal Circulation and Supine Hypotensive Syndrome
Pregnancy leads to a substantial increase in blood volume, which peaks by the third trimester. This elevated blood volume, while essential for nourishing the fetus, also alters the dynamics of maternal circulation.
The average increase in blood volume during pregnancy ranges from 30% to 50%.
When a pregnant woman lies supine (on her back), the enlarged uterus can compress the inferior vena cava (IVC), the major vein that returns blood from the lower body to the heart. This compression reduces venous return, leading to decreased cardiac output and a drop in blood pressure. This condition is known as supine hypotensive syndrome. Symptoms can include dizziness, lightheadedness, nausea, and in severe cases, loss of consciousness.
This syndrome highlights the importance of avoiding the supine position, particularly in the later stages of pregnancy.
Compression of the Inferior Vena Cava by the Growing Uterus
As the uterus grows throughout pregnancy, it exerts increasing pressure on surrounding structures. The IVC, located on the right side of the spine, is particularly susceptible to compression when the woman lies on her back.
The uterus can reach the level of the umbilicus by approximately 20 weeks of gestation.
This compression obstructs blood flow back to the heart, potentially reducing blood supply to both the mother and the fetus. The degree of compression increases as the pregnancy progresses and the uterus enlarges. Prolonged compression can compromise fetal oxygenation and nutrient delivery, emphasizing the need for alternative sleeping positions. The impact is more pronounced in the later stages of pregnancy when the uterus is significantly larger.
Comparison of Blood Flow Efficiency in Different Sleeping Positions
The efficiency of blood flow varies significantly depending on the sleeping position during pregnancy.
- Supine Position: As previously mentioned, this position leads to IVC compression, reduced venous return, and decreased cardiac output. This can result in decreased blood flow to the placenta, potentially impacting fetal well-being.
- Left Lateral Position: This position is generally considered the most beneficial. It minimizes compression of the IVC, optimizing venous return and cardiac output. It also improves blood flow to the placenta. The left lateral position is often recommended as the safest and most effective sleeping posture during pregnancy.
- Right Lateral Position: While generally better than the supine position, the right lateral position can still result in some compression of the IVC, especially in late pregnancy, as the uterus can rotate slightly and press against the vein. The impact is less significant than in the supine position, but the left lateral position is preferred.
Role of Progesterone in Muscle Relaxation and Its Effect on Sleep Posture
Progesterone, a hormone crucial for maintaining pregnancy, also plays a role in relaxing smooth muscles throughout the body. This relaxation can affect sleep posture and comfort.
Progesterone levels increase significantly during pregnancy, reaching levels several times higher than in the non-pregnant state.
This hormonal influence contributes to the relaxation of the ligaments and muscles. While this relaxation is necessary to accommodate the growing uterus, it can also lead to postural changes and discomfort, potentially making it more challenging to maintain a specific sleep position. The combined effect of hormonal changes and the mechanical effects of the growing uterus underscores the importance of adopting a sleep position that optimizes both maternal and fetal health.
Risks Associated with Sleeping on the Back During Pregnancy: When To Stop Sleeping On Back Pregnancy
During pregnancy, particularly in the later stages, the supine sleep position (sleeping on the back) presents several risks to both the mother and the developing fetus. These risks are primarily due to the compression of major blood vessels by the weight of the uterus. Understanding these risks is crucial for promoting maternal and fetal well-being.
Potential Risks to the Fetus Due to Reduced Blood Flow, When to stop sleeping on back pregnancy
Sleeping supine can compromise the blood supply to the fetus. The inferior vena cava, a major vein that carries blood back to the heart from the lower body, can be compressed by the enlarging uterus when a pregnant woman lies on her back. This compression can reduce blood flow to the heart, leading to decreased cardiac output and, consequently, reduced blood flow to the placenta.
The placenta is the lifeline for the fetus, providing oxygen and nutrients.
Reduced placental blood flow can lead to fetal hypoxia (oxygen deprivation), which can have serious consequences for fetal development and well-being.
Prolonged or severe hypoxia can result in:
- Fetal growth restriction.
- Fetal distress during labor.
- Increased risk of stillbirth.
Correlation Between Sleeping on the Back and Stillbirth
Research has indicated a correlation between sleeping on the back during the third trimester and an increased risk of stillbirth. Several studies have explored this relationship, with findings suggesting that the supine sleep position may be a modifiable risk factor.A significant study published inThe Lancet* in 2019, analyzing data from multiple international studies, found a consistent association between late-pregnancy supine sleep and increased stillbirth risk.
The study, involving over 850,000 pregnancies, showed a statistically significant increase in stillbirth rates among women who reported sleeping on their backs in the third trimester. While the exact mechanism is not fully understood, the reduction in blood flow to the placenta is considered a primary contributor. The researchers emphasized the importance of educating pregnant women about alternative sleep positions to potentially mitigate this risk.
Symptoms of Supine Hypotensive Syndrome
Supine hypotensive syndrome (SHS) is a condition that can occur when a pregnant woman lies on her back. The weight of the uterus compresses the inferior vena cava, reducing blood return to the heart. This can lead to a drop in blood pressure, causing a range of symptoms.Symptoms of SHS may include:
- Dizziness or lightheadedness.
- Nausea.
- Shortness of breath.
- Sweating.
- Rapid heartbeat.
- Fainting.
These symptoms are often relieved by changing position, typically by turning onto the left side. Prolonged periods in the supine position can exacerbate these symptoms and potentially compromise maternal and fetal well-being. It is essential for pregnant women to be aware of these symptoms and to change their sleeping position if they experience them.
Comparison of Risks Associated with Different Sleeping Positions
The choice of sleep position during pregnancy significantly impacts both maternal and fetal health. The following table provides a comparison of the risks associated with various sleeping positions:
| Sleeping Position | Risks to the Mother | Risks to the Fetus | Recommendations |
|---|---|---|---|
| Supine (on the back) |
|
|
Avoid sleeping on the back, especially in the later stages of pregnancy. |
| Prone (on the stomach) |
|
|
Avoid sleeping on the stomach as the pregnancy progresses. |
| Left Lateral (on the left side) |
|
|
Recommended sleep position, especially in the third trimester. |
| Right Lateral (on the right side) |
|
|
Acceptable, but the left side is generally preferred. |
Recommended Sleeping Positions During Pregnancy
Maintaining proper sleep posture is crucial throughout pregnancy to ensure both maternal and fetal well-being. Understanding the safest and most comfortable sleeping positions can significantly reduce the risk of complications and promote restful sleep. This section will delve into the recommended sleeping positions, highlighting the benefits of each and providing practical guidance for implementation.
Benefits of Sleeping on the Left Side (LOS) During Pregnancy
Sleeping on the left side is generally considered the optimal sleeping position during pregnancy. This position offers several physiological advantages that contribute to improved maternal and fetal health.
- Enhanced Blood Flow: Sleeping on the left side optimizes blood flow to the placenta, ensuring the fetus receives adequate oxygen and nutrients. This is achieved because the inferior vena cava (IVC), a major vein that carries blood back to the heart, is less compressed when sleeping on the left side compared to the right side or back.
- Reduced Pressure on the Liver: The left side position minimizes pressure on the liver, which is located on the right side of the abdomen. This can help improve liver function and reduce the risk of related discomfort.
- Improved Kidney Function: Sleeping on the left side facilitates kidney function, aiding in the elimination of waste products and reducing swelling in the ankles and feet.
- Decreased Risk of Stillbirth: Research, including studies published in the
-Journal of Physiology*, suggests a correlation between sleeping on the back during the third trimester and an increased risk of stillbirth. Sleeping on the left side is therefore recommended to mitigate this risk.
Transitioning to the Left Side Position Comfortably
Transitioning to the left side position can be challenging, especially if you are accustomed to sleeping in other positions. Gradual adjustments and the use of supportive pillows can make the transition more comfortable and sustainable.
As pregnancy progresses, sleeping on your back becomes increasingly inadvisable. This is due to the pressure on major blood vessels. Many expectant mothers wonder how to monitor their sleep positions, and whether devices like a Fitbit can help. The good news is, you can track sleep quality; you can explore this further by checking out does fitbit measure sleep.
Ultimately, the shift to side sleeping is crucial for both maternal and fetal well-being, especially in the later stages of pregnancy.
- Start Gradually: Begin by practicing sleeping on your left side for short periods during the day, gradually increasing the duration as you become more comfortable.
- Use Pillows for Support: Employ pillows strategically to support your body and maintain the left side position.
- Position a Pillow Between Your Knees: This helps align your hips and reduces strain on your lower back.
- Consider a Pillow Under Your Belly: This provides support for your growing abdomen, preventing you from rolling onto your stomach.
- Experiment with Pillow Placement: Find the pillow arrangement that feels most comfortable and supportive for you.
Using Pillows for Optimal Sleep Posture During Pregnancy
The strategic use of pillows is essential for maintaining proper sleep posture and maximizing comfort during pregnancy. Pillows provide support to the body, alleviate pressure points, and promote restful sleep.
- Between the Knees: A pillow placed between the knees helps align the hips, reducing strain on the lower back and promoting spinal alignment. This is particularly important for side sleepers.
- Under the Belly: A pillow under the belly provides support for the growing abdomen, preventing strain on the abdominal muscles and reducing the risk of discomfort. This is most beneficial in the second and third trimesters.
- Behind the Back: A pillow behind the back helps maintain the side-lying position and prevents rolling onto the back. This is particularly helpful for women who tend to shift positions during sleep.
- Under the Head: A pillow that provides adequate support for the head and neck, ensuring proper spinal alignment. The pillow should be of appropriate height to prevent neck strain.
- Full-Body Pillow: A full-body pillow can offer comprehensive support, aligning the entire body from head to toe. This type of pillow can be particularly helpful for women experiencing significant back pain or discomfort.
Safe Sleeping Positions Besides Left Side
While sleeping on the left side is generally recommended, other positions can be considered safe. However, it is essential to be mindful of the potential risks and prioritize comfort.
- Right Side Sleeping: While not as optimal as the left side, sleeping on the right side is generally considered safe, although blood flow to the placenta may be slightly reduced compared to the left side.
- Semi-Prone Position: This involves sleeping on the side with a slight tilt towards the stomach. This position can be comfortable and can help prevent rolling onto the back. Using pillows to maintain this position is crucial.
- Avoid Sleeping on the Back: Sleeping on the back should be avoided, particularly in the second and third trimesters, as it can compress the inferior vena cava and restrict blood flow to the fetus. If you wake up on your back, gently roll onto your side.
When to Change Sleeping Habits
Understanding the appropriate timing for adjusting sleep habits during pregnancy is crucial for both maternal and fetal well-being. This involves recognizing the physiological changes throughout the trimesters and being attentive to the body’s signals. This section will Artikel the general guidelines and provide insights into when to transition away from sleeping on the back.
General Timeframe for Avoiding Back Sleeping
The general recommendation is to start avoiding sleeping on the back, ideally, from the second trimester onward. This is because the growing uterus begins to exert significant pressure on the inferior vena cava (IVC) during this period. The IVC is a major blood vessel that returns blood from the lower body to the heart. Compression of the IVC can reduce blood flow to the heart, potentially leading to decreased blood flow to the uterus and the developing fetus.
Some women may experience symptoms even earlier, making it essential to be aware of the body’s signals and adjust accordingly.
Body Changes Influencing Sleep Position by Trimester
The changes in a woman’s body during each trimester significantly influence the comfort and safety of sleep positions.
- First Trimester: During the first trimester, the uterus is still relatively small, and sleeping on the back may not pose a significant risk for most women. However, some women may experience early symptoms of IVC compression, such as dizziness or lightheadedness, even at this stage. Additionally, hormonal changes can lead to increased fatigue and breast tenderness, making alternative sleep positions more comfortable.
- Second Trimester: The second trimester marks a significant shift. The uterus expands more noticeably, increasing the pressure on the IVC when lying supine (on the back). This can lead to decreased blood flow to the mother and the baby. The mother may begin to experience shortness of breath, dizziness, or a rapid heartbeat when sleeping on her back.
- Third Trimester: In the third trimester, the uterus is at its largest, and the risk of IVC compression is at its highest. Sleeping on the back is generally considered unsafe at this stage. The weight of the uterus can also compress other organs, such as the intestines, potentially leading to digestive discomfort.
Early Signs to Consider Changing Sleeping Position
Paying attention to the body’s signals is paramount. Several early signs can indicate that a pregnant woman should consider changing her sleeping position.
- Dizziness or Lightheadedness: This can be a sign of reduced blood flow to the brain, potentially caused by IVC compression.
- Shortness of Breath: Difficulty breathing while lying on the back can also indicate that the IVC is being compressed, restricting blood flow to the heart and lungs.
- Rapid Heartbeat: An increased heart rate can be a response to the body’s attempt to compensate for reduced blood flow.
- Back Pain: The growing uterus can put additional strain on the back muscles, exacerbating back pain when sleeping on the back.
- Digestive Discomfort: Heartburn or indigestion may worsen when lying on the back due to pressure on the stomach and esophagus.
Impact of Baby’s Growth on Sleep Position
The baby’s growth directly impacts the mother’s ability to sleep on her back. As the baby grows, the uterus expands, increasing the pressure on the IVC. The weight of the baby and the amniotic fluid further contribute to this pressure.
The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women avoid sleeping on their back, especially in the second and third trimesters, to prevent potential complications.
For example, imagine a woman at 20 weeks gestation. The uterus is starting to grow significantly, and the baby is now large enough to potentially compress the IVC. This is the stage where the woman should start being more conscious of her sleeping position and begin to transition to sleeping on her side. At 30 weeks gestation, the uterus is significantly larger, and the pressure on the IVC is even greater, making back sleeping highly inadvisable.
By 36 weeks, the baby is almost fully developed, and the woman’s comfort and safety are greatly compromised when sleeping on her back. The woman will likely experience difficulty breathing, and any prolonged pressure on the IVC could have significant consequences.
Methods for Avoiding Back Sleeping
Preventing supine sleep during pregnancy is crucial for maternal and fetal well-being. Several practical strategies can be employed to minimize the risk of inadvertently sleeping on the back. These methods primarily focus on modifying sleep posture through environmental adjustments and the use of assistive devices.
Strategies for Preventing Back Sleeping
Implementing a multi-faceted approach to avoid back sleeping is recommended. This involves creating a sleep environment that actively discourages the supine position.
- Utilizing Sleep Position Monitors: These devices, often wearable or placed on the mattress, alert the sleeper when they roll onto their back. Some monitors vibrate or emit a sound to prompt a position change. These are particularly useful for individuals with a history of unconscious back sleeping.
- Employing Pillow Barriers: Strategically placing pillows along the back can physically prevent the body from rolling over. A firm pillow or rolled-up towel can act as a barrier. This is a simple and cost-effective method.
- Modifying Sleepwear: Sewing a pocket on the back of sleepwear to hold a tennis ball or a similar object can make back sleeping uncomfortable. The discomfort acts as a deterrent.
- Adjusting Mattress Support: While not directly preventing back sleeping, ensuring proper mattress support is crucial. A mattress that conforms to the body’s contours can make side sleeping more comfortable and reduce the likelihood of tossing and turning, which can lead to unintentional back sleeping.
- Practicing Sleep Hygiene: Establishing a consistent sleep schedule and avoiding caffeine and alcohol before bed can improve sleep quality, which in turn reduces the chances of restless sleep and unintentional posture changes.
Use of Pillows and Aids for Side-Sleeping
Pillows play a pivotal role in promoting and maintaining a comfortable and safe side-sleeping position during pregnancy. Various types of pillows can be utilized to provide support and alleviate pressure points.
- Body Pillows: These long, full-length pillows are designed to support the entire body, including the head, neck, back, abdomen, and legs. They are a highly effective method for maintaining side sleeping.
- Pregnancy Pillows: Specifically designed for pregnant women, these pillows come in various shapes, such as C-shaped, U-shaped, and wedge pillows, to provide targeted support.
- Wedge Pillows: These smaller pillows can be placed under the abdomen or back to provide support and prevent rolling onto the back.
- Standard Pillows: While not specifically designed for pregnancy, standard pillows can be used in conjunction with other aids to provide head and neck support.
Guide to Using a Body Pillow Effectively
A body pillow can significantly enhance sleep comfort and ensure proper alignment during pregnancy. Proper utilization is key to maximizing its benefits.
- Positioning: Place the body pillow along the entire length of the body, with the head resting on the pillow.
- Head Support: Ensure the head and neck are supported by the pillow, maintaining a neutral spinal alignment.
- Abdominal Support: Place a portion of the pillow under the abdomen to provide support and reduce strain on the back.
- Leg Support: Keep one leg draped over the pillow, with the knee bent. This helps align the hips and reduces pressure on the lower back.
- Adjustments: Experiment with different positions and adjustments to find the most comfortable and supportive arrangement.
Illustration of Side Sleeping with Pillow Support
The following describes a pregnant woman comfortably side-sleeping with proper pillow support:The illustration depicts a woman in her second trimester, lying on her left side. She is draped in a light, breathable fabric. A long, U-shaped body pillow cradles her body. The top of the pillow supports her head and neck, maintaining a straight alignment from her ear to her shoulder.
Her left arm rests comfortably along the pillow, with her left hand near her face. Her left leg is straight, resting against the lower part of the pillow. Her right leg is bent at the knee and rests over the pillow, providing support to her abdomen and maintaining the alignment of her hips. A small wedge pillow is placed behind her back, gently preventing her from rolling onto her back.
Her facial expression is relaxed, indicating comfort and restful sleep. The lighting is soft, creating a calming atmosphere.
Seeking Professional Advice
It is crucial for pregnant women to prioritize their health and the well-being of their developing baby. Consulting a healthcare provider is an essential step in navigating the physical changes and potential complications of pregnancy, especially concerning sleep. Timely professional guidance ensures appropriate management of any concerns and promotes a healthy pregnancy.
When to Consult a Doctor About Sleep Position
A pregnant woman should consult her doctor about her sleep position at several key points throughout her pregnancy. Early consultation allows for proactive measures and personalized advice.
- At the Initial Prenatal Visit: Discussing sleep position at the first prenatal appointment allows the healthcare provider to assess the patient’s baseline sleep habits and address any pre-existing concerns.
- As the Pregnancy Progresses: As the pregnancy advances and the woman’s body changes, particularly in the second and third trimesters, periodic check-ins regarding sleep position are essential. The doctor can offer tailored advice based on the stage of pregnancy.
- If Experiencing Discomfort or Difficulty Sleeping: Any persistent discomfort, difficulty falling asleep, or changes in sleep patterns should prompt a consultation. These symptoms can be early indicators of potential issues related to sleep position or underlying health conditions.
- If Concerned About Fetal Movement: Any noticeable decrease in fetal movement, especially after changing sleep positions, necessitates immediate medical attention.
Symptoms Warranting Immediate Medical Attention Related to Sleep
Certain symptoms related to sleep during pregnancy require prompt medical evaluation. These symptoms can indicate serious complications that could affect both the mother and the fetus.
- Severe Shortness of Breath: Difficulty breathing, especially when lying down, could be a sign of underlying cardiac or pulmonary issues, requiring immediate intervention.
- Chest Pain: Any chest pain, whether sharp or dull, should be reported to a doctor immediately. It could indicate a cardiovascular problem.
- Dizziness or Fainting: Experiencing dizziness or fainting spells, particularly when changing positions, warrants immediate medical evaluation to rule out preeclampsia or other serious conditions.
- Unusual Swelling: Sudden or excessive swelling, particularly in the hands, face, or ankles, can be a symptom of preeclampsia.
- Severe Headaches: Persistent or severe headaches, especially if accompanied by vision changes, are concerning and need prompt medical assessment.
- Decreased Fetal Movement: A noticeable reduction in fetal movement is a critical sign that requires immediate medical attention. The doctor will assess fetal well-being.
- Vaginal Bleeding: Any vaginal bleeding, regardless of the amount, during pregnancy necessitates immediate medical evaluation.
The Role of Healthcare Providers in Advising on Safe Sleeping Practices
Healthcare providers play a crucial role in educating and guiding pregnant women on safe sleeping practices. They provide personalized advice based on the individual’s health status and the stage of pregnancy.
- Assessment of Medical History: Doctors will review the patient’s medical history to identify any pre-existing conditions that might influence sleep recommendations.
- Explanation of Risks: They explain the potential risks associated with sleeping on the back during pregnancy and the benefits of alternative positions.
- Recommendation of Optimal Sleep Positions: Healthcare providers recommend the left-side sleeping position as the safest and most beneficial for both the mother and the fetus.
- Guidance on Using Support: Doctors may suggest using pillows to support the body and maintain the recommended sleeping position. They can provide advice on how to use pillows effectively.
- Addressing Concerns: Healthcare providers address any concerns the patient may have about sleep and provide individualized solutions.
- Monitoring Fetal Well-being: In certain situations, the doctor may monitor fetal well-being, especially if the mother is experiencing complications.
Questions a Pregnant Woman Should Ask Her Doctor About Sleep
Pregnant women should actively engage with their healthcare providers to gather comprehensive information about sleep. Preparing a list of questions can facilitate a productive discussion.
- What is the safest sleep position for me and my baby? This question is fundamental to understanding the best practices for sleep during pregnancy.
- How can I comfortably transition to sleeping on my side? This question seeks practical advice on how to adopt the recommended sleep position.
- Are there any specific risks associated with my current sleep position? This allows the doctor to address any concerns based on the patient’s specific circumstances.
- What are the signs of a problem related to sleep that I should be concerned about? This question helps the patient identify warning signs that warrant immediate medical attention.
- Should I be concerned about a change in fetal movement related to my sleep position? This question directly addresses the relationship between sleep position and fetal well-being.
- What can I do if I wake up on my back? This question provides practical guidance for managing accidental back sleeping.
- Can you recommend any specific pillows or support devices to help me sleep comfortably? This question seeks practical solutions for enhancing sleep quality.
- How often should I follow up with you about my sleep concerns? This establishes the frequency of check-ins to monitor progress and address any new concerns.
End of Discussion
In conclusion, navigating the complexities of sleep during pregnancy requires vigilance and informed decision-making. Recognizing the physiological impacts of various sleeping positions, particularly the risks associated with supine sleeping, is paramount. By embracing the recommended practices, such as sleeping on the left side and utilizing supportive aids, expectant mothers can significantly mitigate potential risks. Prioritizing safe sleep habits is an essential aspect of prenatal care, contributing to the overall health and well-being of both mother and child, ensuring a healthier pregnancy journey.
FAQ Guide
At what stage of pregnancy is it generally recommended to stop sleeping on your back?
Most healthcare providers advise against sleeping on the back, ideally, starting from the second trimester, typically around 20 weeks of gestation, when the uterus begins to significantly enlarge.
What are the immediate signs that indicate a pregnant woman should change her sleeping position?
Symptoms such as dizziness, shortness of breath, and lightheadedness when lying on the back are clear indicators to immediately change position. Fetal movement changes or decreased activity should also prompt a change.
Is there a risk of rolling onto my back while sleeping, and what can I do to prevent this?
Yes, there is a risk, particularly in the later stages of pregnancy. To prevent rolling onto your back, use pillows strategically placed behind your back and between your knees. Consider using a body pillow to maintain a side-sleeping position throughout the night.
When should I consult my doctor about my sleep position during pregnancy?
Consult your doctor if you experience any concerning symptoms related to your sleep position, such as persistent dizziness, breathing difficulties, or if you have any doubts or concerns about your sleeping habits. Any reduction in fetal movement should also prompt a call to your doctor.
Are there any other sleeping positions besides the left side that are considered safe?
While the left side is often recommended, the right side is generally considered safe. However, sleeping on either side is preferable to sleeping on your back.
