Getting comfortable in bed during pregnancy comes down to reducing pressure on your hips, supporting your belly, and finding a sleep position that works as your body changes week by week. Most discomfort starts in the second trimester and intensifies in the third, but the right combination of pillows, bedding, and positioning can make a real difference in how well you sleep.
Sleep Position After 28 Weeks
For the first half of pregnancy, you can sleep in whatever position feels comfortable. The position conversation becomes more important in the third trimester. A large New Zealand case-control study found that falling asleep on your back after 28 weeks was associated with a 3.7-fold increase in late stillbirth risk, with the risk climbing even higher after 37 weeks. The key finding: it’s your “going-to-sleep” position that matters most, not what you shift into overnight. Your body will naturally move during the night, and that’s fine.
Side sleeping is the standard recommendation for the third trimester. You may have heard that the left side is specifically better because it takes pressure off a major vein that returns blood to your heart. The reality is more nuanced. A review in the Journal of Obstetrics and Gynaecology Canada found that only 2% to 4% of women who lie on their backs experience significant compression of that vein, and even in those cases, there was no evidence of harm to the baby. So while side sleeping is the safer default after 28 weeks, don’t stress about which side you’re on. Either works. If you wake up on your back, simply roll to your side and settle back in.
How to Support Your Body With Pillows
A pillow between your knees is the single most effective change for hip and lower back comfort. It keeps your pelvis aligned so your top leg doesn’t pull your spine out of position. A regular bed pillow works, but a firmer one holds its shape better through the night. Place it so it runs from mid-thigh to just below your knees.
Beyond the knee pillow, a small pillow or rolled towel tucked under your belly prevents the weight of your uterus from pulling you forward. This is especially helpful from the late second trimester onward, when your belly is heavy enough to create a noticeable tug on your lower back even while lying down.
If you want a single product that does everything, full-body pregnancy pillows come in two main designs:
- U-shaped pillows cradle your entire body, supporting your head, back, belly, hips, and knees at once. They’re ideal if you switch sides during the night because you don’t have to reposition the pillow. The tradeoff is size: they take up a lot of bed space, which can be a problem if you share.
- C-shaped pillows are more compact and offer targeted support. They tuck between your knees and curve up to support your belly or back. They work well for dedicated side sleepers and leave more room for a partner.
If you’re on a budget, three regular pillows (one behind your back, one under your belly, one between your knees) accomplish the same goal. The advantage of a pregnancy pillow is that everything stays in place when you shift positions.
Relieving Hip Pain on a Firm Mattress
Side sleeping puts concentrated pressure on your hip and shoulder, and that pressure gets worse as pregnancy weight increases. If you’re waking up with sore hips, the problem is usually your mattress surface, not your position.
A memory foam mattress topper, 3 to 4 inches thick, is the most commonly recommended fix. The foam distributes your weight across a wider area so your hip doesn’t bear the brunt. One important caveat: if your mattress already sags in the middle, a topper can make that worse by conforming to the dip rather than correcting it. In that case, placing a flat board under the mattress or flipping it (if possible) before adding the topper will give you better results. Gel-infused memory foam is worth considering because standard memory foam traps heat, which compounds the temperature issues many pregnant women already deal with.
Managing Heartburn at Night
Heartburn tends to peak in the third trimester as your growing uterus pushes your stomach upward and the hormone relaxin loosens the valve at the top of your stomach. Lying flat makes it worse because gravity no longer keeps acid down.
A wedge pillow is the most effective solution. Look for one that elevates your head 6 to 12 inches at a 30- to 45-degree angle. This keeps your esophagus above your stomach so acid stays put. If you’re a side sleeper, a memory foam wedge with a contoured incline is more comfortable than a rigid foam block, which can create pressure points at your shoulder. You can also achieve a similar effect by placing risers under the head of your bed frame, which tilts the entire sleeping surface and feels more natural than sleeping propped up on stacked pillows (which tend to bend you at the waist and can actually increase abdominal pressure).
Eating your last meal at least two to three hours before bed and avoiding acidic or spicy foods in the evening reduces the amount of acid available to reflux in the first place.
Staying Cool Through the Night
Increased blood volume and hormonal shifts raise your core body temperature during pregnancy, and many women experience night sweats starting in the second trimester. Your bedding plays a bigger role than room temperature alone.
Cotton sheets absorb moisture but hold onto it, leaving you sleeping in damp fabric. Bamboo viscose is a better option for temperature regulation. Its naturally porous fibers promote airflow and actively wick sweat to the surface where it can evaporate, rather than trapping it against your skin. Bamboo sheets in the 250 to 300 thread count range provide softness comparable to high-thread-count cotton while allowing significantly more ventilation. They also adapt to body temperature changes, cooling you during hot flashes without leaving you cold afterward.
If you’ve added a memory foam topper for hip relief, pairing it with breathable sheets matters even more, since memory foam retains heat. A lightweight cotton or bamboo blanket instead of a heavy comforter, plus keeping your room around 65 to 68°F, rounds out the cooling strategy.
Dealing With Restless Legs and Cramps
Restless legs syndrome affects up to one in three pregnant women, typically worsening at night. That creeping, tingling urge to move your legs can make it nearly impossible to fall asleep, even when the rest of your body is comfortable.
Low iron and magnesium levels are the most common contributors during pregnancy. A 2022 randomized trial found that 250 mg of magnesium paired with vitamin B6 improved restless leg symptoms starting after the first month of supplementation. Magnesium citrate at 200 mg daily has also shown positive results in clinical trials. Talk with your provider about checking your iron and magnesium levels, since supplementing without knowing your baseline can cause its own problems (too much magnesium causes diarrhea, for instance).
In the meantime, gentle calf stretches before bed help. Stand facing a wall, step one foot back, and press the heel into the floor with your back knee straight for 30 seconds per side. A warm (not hot) bath before bed also relaxes the muscles and reduces the frequency of nighttime cramps. Some women find that keeping a cool pack near the foot of the bed helps interrupt the restless sensation when it starts.
A Practical Setup for Each Trimester
In the first trimester, most women don’t need to change anything yet. Sleep in whatever position is comfortable. If nausea is keeping you up, a slight incline from a wedge pillow can help settle your stomach.
By the second trimester, start introducing a pillow between your knees and consider a mattress topper if hip soreness appears. This is also a good time to switch to breathable sheets if night sweats have started. Getting used to side sleeping now makes the transition easier later.
In the third trimester, combine everything: side sleeping with full pillow support (knees, belly, and back), a wedge for heartburn if needed, and cooling bedding. Keep water within reach since you’ll likely wake for bathroom trips anyway, and staying hydrated helps with leg cramps. If you find yourself dreading bedtime because of discomfort, try spending 10 minutes before getting into bed doing gentle stretches for your hips and calves. It loosens the muscles that tighten from carrying extra weight all day and makes that first settling-in position feel noticeably better.