The second trimester is when sleep starts getting complicated. Your belly is growing enough to make your usual positions uncomfortable, but you’re not yet in the final stretch where exhaustion takes over. Side sleeping is the best position during your second and third trimesters, and a few strategic adjustments to your pillow setup, fluid timing, and bedtime routine can make a real difference in how well you rest.
Why Side Sleeping Matters Now
As your uterus grows, it becomes heavy enough to press on the large vein that carries blood back to your heart when you lie flat on your back. This compression reduces the amount of blood returning to your heart, which in turn lowers blood flow to your uterus and the oxygen reaching your baby. The American College of Obstetricians and Gynecologists recommends side sleeping during the second and third trimesters for this reason.
A meta-analysis published in The Lancet’s eClinicalMedicine found that going to sleep on your back after 28 weeks was associated with 2.6 times higher odds of late stillbirth compared to falling asleep on your left side. That sounds alarming, but context matters: the overall risk of stillbirth is low, and the study looked at the position you fall asleep in, not every position you shift into overnight. The practical takeaway is simple. Make a habit of falling asleep on your side now, in the second trimester, so it feels natural by the time it matters most.
Either side works. You don’t need to stay exclusively on your left. Sleeping on your right side is also safe. The key is avoiding prolonged time flat on your back, especially as you move into the later weeks.
How to Set Up Your Pillows
The right pillow arrangement turns side sleeping from tolerable to genuinely comfortable. Think of it as building support at four points: head, belly, knees, and back.
- Between your knees: Place a pillow (or two) between your knees, thighs, and feet so your upper leg sits level with your pelvis and mirrors the position of your bottom leg. This keeps your hips aligned and prevents the pulling sensation across your lower back and pelvis that wakes many people up.
- Under your belly: A small rolled towel or thin pillow tucked under your abdomen supports the weight of your growing uterus so it doesn’t drag forward and strain your back.
- Along your spine: If you tend to roll onto your back during the night, a firm pillow wedged behind you acts as a physical reminder. A rolled towel placed between your ribs and hips can also relieve pressure along your side.
- Under your head and upper body: If heartburn or nasal congestion is a problem, elevate your head and trunk with a wedge pillow or stack of cushions. A 4 to 6 inch elevation is enough to keep stomach acid from creeping up while you sleep.
Full-length pregnancy pillows (C-shaped or U-shaped) essentially handle all of this in one piece. They’re worth trying if you find yourself rearranging four separate pillows every time you shift positions.
Dealing With Heartburn at Night
Heartburn tends to show up in the second trimester as your growing uterus pushes your stomach upward and the hormones of pregnancy relax the valve between your esophagus and stomach. Lying flat makes it worse because gravity is no longer helping keep acid down.
Elevating the head of your bed by 4 to 6 inches, or using a wedge pillow under your upper body, is the most effective sleeping adjustment. Propping yourself up with regular pillows can work, but you’re more likely to slide down overnight. Eating your last meal at least two to three hours before bed and avoiding spicy, acidic, or fatty foods in the evening also helps. Small, frequent meals during the day reduce the amount of acid your stomach produces at any one time.
Reducing Nighttime Bathroom Trips
Your kidneys are filtering about 50% more blood volume during pregnancy, which means more urine production. Add a growing uterus pressing on your bladder, and waking up two or three times a night to pee is common by mid-pregnancy.
You need 8 to 12 cups of water per day during pregnancy, so cutting fluids drastically isn’t the answer. Instead, front-load your hydration. Drink most of your water during the morning and afternoon, then taper off a few hours before bed. When you do wake up, keep the lights as dim as possible. Bright light suppresses the hormone that helps you fall back asleep, turning a quick bathroom trip into a wide-awake hour.
Managing Leg Cramps
Sudden, painful cramping in your calves, often striking in the middle of the night, is one of the more disruptive sleep problems of the second trimester. Lower calcium and magnesium levels during pregnancy may contribute, though research on the exact cause is mixed.
If a cramp hits, flex your foot by pulling your toes toward your shin to stretch the calf muscle. Walking for a minute afterward, then sitting with your legs elevated, helps prevent it from returning. A warm bath or ice massage on the muscle can also ease the soreness that lingers.
For prevention, stretching your calves before bed is the most consistently helpful strategy. Staying active during the day and keeping well hydrated (your urine should be clear or light yellow) also reduces cramping frequency. Magnesium-rich foods like nuts, seeds, beans, whole grains, and dried fruits are worth adding to your diet. A magnesium supplement is another option, though the evidence for it is mixed, so it’s worth discussing with your provider first. Aim for 1,000 milligrams of calcium daily from food and supplements combined.
Clearing Up Nasal Congestion
Pregnancy rhinitis, chronic stuffiness caused by increased blood flow and swelling in your nasal passages, affects roughly one in five pregnant people. It has nothing to do with a cold or allergies and can last for weeks or months. At night, it forces mouth breathing, which dries your throat and disrupts sleep quality even when you don’t fully wake up.
Saline nasal rinses using a neti pot or squeeze bottle are the safest first step and often provide enough relief to breathe comfortably through the night. Sleeping with your head slightly elevated also helps, since lying flat increases nasal swelling. Running a humidifier in your bedroom keeps mucous membranes from drying out further. Decongestant nasal sprays are generally considered safe during pregnancy for short-term use (a few days), but using them longer can cause rebound congestion that makes the problem worse. Oral decongestants require more caution, so check with your provider before taking those.
Building a Sleep-Friendly Routine
Position and pillows matter, but the basics of sleep hygiene become more important during pregnancy because you’re already working against hormonal shifts, physical discomfort, and anxiety that can keep your brain buzzing at 2 a.m.
Keep your bedroom cool. Your core body temperature runs higher during pregnancy, and a warm room makes it harder to fall asleep and stay asleep. Somewhere around 65 to 68°F works for most people. Go to bed and wake up at roughly the same time every day, even on weekends. This consistency reinforces your body’s internal clock and makes falling asleep easier over time.
If you can’t fall asleep within about 20 minutes, get up and do something quiet in low light, like reading a physical book, then return to bed when you feel drowsy. Lying in bed awake trains your brain to associate the bed with frustration rather than sleep. Light physical activity during the day, even a 20 to 30 minute walk, improves sleep quality, though you’ll want to finish any vigorous movement at least a few hours before bedtime.
Naps are fine and sometimes necessary, but keep them to 20 to 30 minutes before mid-afternoon. Longer or later naps can chip away at your ability to fall asleep at night, creating a cycle that’s hard to break.