At 38 weeks pregnant, getting comfortable enough to fall asleep can feel nearly impossible. Between a full-sized belly, frequent bathroom trips, heartburn, and restless legs, most women at this stage are waking multiple times per night. The good news: a combination of the right sleep position, pillow setup, and a few targeted strategies can make a real difference in the hours you have left before delivery.
Why Sleep Gets So Hard at 38 Weeks
Your uterus is now roughly the size of a watermelon, and it’s pressing on nearly every organ in your abdomen. Your bladder has less room, which means more nighttime trips to the bathroom. Your diaphragm is compressed, making breathing feel shallower. Hormonal shifts increase your core body temperature, and the relaxation of your esophageal muscles lets stomach acid creep upward more easily. On top of all that, your body is producing hormones that loosen your pelvic joints in preparation for labor, which can cause aching hips and lower back pain the moment you lie down.
These aren’t problems you can fully solve. But you can manage each one well enough to string together longer stretches of rest.
The Best Sleeping Position
Side sleeping is the standard recommendation for late pregnancy. Most physicians specifically advise the left side. The reason is mechanical: at 38 weeks, your uterus is heavy enough to compress major blood vessels when you lie on your back, including the large vein that returns blood from your lower body to your heart and the main artery that delivers blood to your uterus and baby. This compression can reduce blood flow and has been linked in studies to a higher risk of stillbirth, reduced fetal growth, low birth weight, and preeclampsia.
Research confirming that back sleeping is safe was only conducted up to 30 weeks of pregnancy. Beyond that point, the evidence still supports side sleeping as the safest option. If you wake up on your back in the middle of the night, don’t panic. Simply roll to your side. The risk comes from prolonged back sleeping, not a few minutes of shifting positions during the night.
Right-side sleeping is generally fine too, though left is slightly preferred because it keeps the weight of the uterus off your liver and may optimize blood flow to the placenta.
Pillow Setup That Actually Helps
The right pillow arrangement does more than add comfort. It keeps your hips and spine aligned, which reduces the pelvic and lower back pain that wakes you up. The ideal side-lying setup has three components: a pillow between your knees and ankles to keep your hips level, a cushion or folded pillow tucked under your belly to support its weight, and something behind your back to prevent you from rolling onto it during sleep.
A full-length pregnancy pillow can do all three jobs at once, or you can use a combination of regular pillows. If you’re dealing with heartburn, add an extra pillow under your head or use a small wedge pillow to elevate your upper body. Even a slight incline helps keep stomach acid from rising into your esophagus.
Managing Nighttime Heartburn
Heartburn affects the majority of women by the third trimester, and it tends to be worst at night when you’re lying flat. A few changes to your evening routine can cut down on it significantly. Eat smaller meals in the evening rather than one large dinner, and avoid lying down for at least two to three hours after eating. Spicy foods, tomato-based sauces, and acidic or fatty meals are common triggers worth skipping until after delivery.
If dietary changes aren’t enough, calcium carbonate antacids are safe during pregnancy and can be taken at standard doses without adjustment. They have the added benefit of supplementing your calcium intake. If antacids alone aren’t controlling your symptoms, over-the-counter acid reducers like famotidine are also considered safe in pregnancy and provide longer-lasting relief.
Cutting Down on Bathroom Trips
Frequent urination at 38 weeks is largely unavoidable because the baby’s head is sitting directly on your bladder. But you can reduce nighttime trips by front-loading your water intake earlier in the day. Try to get most of your fluids before late afternoon, then taper off in the two to three hours before bed. Don’t cut water intake overall, though. Many pregnant women actually underhydrate because they’re trying to avoid bathroom trips, which can lead to other problems like dehydration headaches and constipation.
When you do use the bathroom before bed, lean forward slightly while sitting on the toilet. This helps your bladder empty more completely by shifting the baby’s weight off it, which can buy you an extra hour or two before your next trip.
Dealing With Restless Legs
That creeping, crawling urge to move your legs just as you’re trying to fall asleep is extremely common in late pregnancy. Non-drug approaches are the primary recommended treatment during pregnancy. Moderate exercise earlier in the day, gentle yoga, calf stretches before bed, and leg massage have all shown benefit. Some women find that alternating warm and cool compresses on their legs helps, or simply getting up to walk around or do a few squats when symptoms flare.
Reducing caffeine and salt intake may also ease symptoms. You might see magnesium supplements recommended online, but there’s actually no strong evidence that magnesium helps restless legs during pregnancy. If your symptoms are severe enough to prevent sleep most nights, it’s worth bringing up at your next appointment since iron deficiency can be a contributing factor and is easily tested for.
Keeping Your Bedroom Cool
Your body runs warmer during pregnancy thanks to increased blood volume and hormonal changes, and by 38 weeks many women experience waves of heat that make it hard to stay comfortable. The recommended bedroom temperature for quality sleep is 60 to 67°F (15 to 19°C). Anything above 70°F is generally too warm, and that threshold is even more relevant when you’re pregnant.
Keep a fan running for air circulation, wear breathable pajamas (cotton or moisture-wicking fabric), and use lightweight, layered bedding so you can kick off a layer without waking your partner. Some women find that keeping a cold water bottle on the nightstand or placing a cool, damp washcloth on the back of their neck helps during hot flashes.
Relaxation Strategies for a Racing Mind
At 38 weeks, anxiety about labor, delivery, and life with a newborn can keep your brain spinning long after your body is ready for sleep. A consistent wind-down routine signals your body that it’s time to shift gears. Dim the lights in your home about an hour before bed, put screens away, and do something low-stimulation like reading, gentle stretching, or listening to a sleep meditation.
If you find yourself lying awake for more than 20 minutes, get up, move to a dim room, and do something quiet until you feel drowsy again. Staying in bed while frustrated trains your brain to associate the bed with wakefulness rather than sleep.
Sleep Aids and Supplements
Non-drug approaches are always preferred during pregnancy, but when sleeplessness becomes unbearable, some options carry relatively low risk. Diphenhydramine (the active ingredient in many over-the-counter sleep aids and allergy medications) has been used in pregnancy and is not expected to increase the risk of birth defects based on animal studies. One clinical trial found it improved both sleep duration and sleep quality compared to placebo. That said, using it in late pregnancy carries a small risk of withdrawal symptoms in newborns, so it’s not something to take nightly without guidance from your provider.
Melatonin is a more complicated picture. Reviews of clinical studies suggest it is probably safe during pregnancy, and it has low toxicity overall. But researchers have not found trials specifically testing melatonin for pregnancy insomnia, so there’s no clear consensus on whether it’s effective or what dose is appropriate this close to your due date.
When Contractions Wake You Up
Waking up to contractions at 38 weeks is common, and in most cases they’re Braxton Hicks, not labor. The key differences: Braxton Hicks contractions come at random intervals, feel like mild tightening or menstrual-like cramping across the front of your belly, and ease up if you change positions, drink water, or take acetaminophen. Real labor contractions develop a steady, increasingly frequent rhythm, grow more painful over time, and are felt not just in front but also in your hips, lower back, and cervix.
If you’re unsure, time them. Labor contractions will get closer together and won’t let up no matter what you do. Other signs that labor has started include your water breaking, losing your mucus plug, or light bleeding (less than a typical period). Heavy bleeding, more than you’d see during a normal period, is a reason to head to the hospital right away.