Sleep during pregnancy is one of the great cruel ironies: your body desperately needs more rest, while simultaneously making rest harder to achieve. Between the hip pain, the back ache, the bathroom trips, the restless legs and the sheer physical challenge of getting comfortable with a growing bump — it's a lot. But many of the biggest sleep disruptors during pregnancy are directly addressable with the right information and the right support.
The Most Important Pregnancy Sleep Rule: Sleep On Your Side
From 28 weeks, Australian midwives and RANZCOG (Royal Australian and New Zealand College of Obstetricians and Gynaecologists) recommend sleeping on your side rather than your back. Research has associated back sleeping in the third trimester with increased risk of stillbirth, thought to be related to the weight of the uterus compressing major blood vessels (the aorta and inferior vena cava) and reducing circulation.
Left-side sleeping is generally preferred as it supports optimal blood flow to the kidneys and uterus. Right-side sleeping is considered safe. What matters most is avoiding flat back sleeping in the later trimesters.
How to Sleep During Each Trimester
First Trimester (Weeks 1–13)
Your bump isn't yet significant, so position isn't medically critical. However, now is the ideal time to establish the side-sleeping habit. Your body isn't under significant postural stress yet, which makes it much easier to adapt. Starting a side-sleeping routine and introducing a pregnancy pillow in the first trimester means it feels natural by the time you actually need it. First trimester sleep is also disrupted by nausea, fatigue and heightened anxiety — going to bed with a comfortable, familiar setup makes a real difference.
Second Trimester (Weeks 14–27)
This is when bump size starts to matter for sleep. Belly-sleeping becomes uncomfortable and then impossible. Back sleeping starts to feel odd — many women notice a heaviness or shortness of breath when lying flat from around 20 weeks. Side sleeping with belly support becomes essential. Round ligament pain (sharp side-of-abdomen pain as the uterus ligaments stretch) peaks here and is directly worsened by unsupported side sleeping. Hip pain typically emerges in this trimester as well.
Third Trimester (Weeks 28–40)
Side sleeping is now the only practical option, and the medical recommendation is clear and firm. Hip pain, lower back ache, pelvic pressure, sciatic nerve pain, and leg cramps all peak in this trimester. Bathroom trips increase. Heartburn interrupts sleep in the later weeks. Full-body support from a properly designed pregnancy pillow reduces the number of times you wake up due to pain and the time it takes to get comfortable when you do.
Setting Up for Better Pregnancy Sleep
Use a dedicated pregnancy support pillow
The single most impactful change most women make. Stacking regular pillows works temporarily but they move, compress and require constant rearranging. A full-body S-curve pregnancy pillow supports the bump, lower back and knees simultaneously without needing to be rebuilt every time you shift position.
Elevate the head of your bed slightly for heartburn
Third trimester heartburn disrupts sleep more than most people anticipate. A slight elevation of the head (10–15cm) reduces acid reflux during sleep without requiring you to sleep in an awkward propped position. Sleeping wedges or adjustable bed risers help here.
Keep the room cool
Body temperature rises during pregnancy, particularly in the third trimester. A room temperature between 18–20°C supports better sleep. Use breathable cotton or bamboo bedding and consider a pregnancy pillow with a breathable cover rather than a synthetic one.
Limit fluids in the two hours before bed
You'll never eliminate bathroom trips in late pregnancy, but reducing fluid intake in the final two hours before bed reduces the frequency. Front-loading hydration earlier in the day maintains overall intake while reducing sleep interruptions.
Ergo Sleep™ S-Shape Pregnancy Pillow
The full-body support pillow for every trimester. 2,400+ five-star reviews · Free AU shipping · 60-day returns.
1 Pillow — $69 2 Pillows — $119Frequently Asked Questions
Is it dangerous to sleep on your back during pregnancy?
From 28 weeks, regular back sleeping is associated with increased risk and is not recommended by Australian midwife guidelines. If you occasionally wake up on your back, this isn't a cause for panic — simply return to your side. The concern is about sustained back sleeping during the third trimester, not momentary position changes during sleep.
Why can't I get comfortable in any position during the third trimester?
In late pregnancy, virtually every position creates some form of discomfort — the bump is large, the pelvis is unstable, and the body is under significant load. The goal shifts from finding the perfect comfortable position to finding the least uncomfortable position with the best support. A full-body pregnancy pillow significantly raises the baseline comfort level across all side-sleeping positions.
Can I sleep on my right side during pregnancy?
Yes — right-side sleeping is considered safe during pregnancy. Left side is preferred by many guidelines due to its effect on circulation, but the most important thing is sleeping on your side (rather than your back), not which specific side. If left-side hip pain is significant, alternating sides through the night is widely considered acceptable.
When does pregnancy insomnia usually start?
Sleep disruption often begins as early as the first trimester with fatigue and nausea. It tends to ease in the second trimester before returning in full force in the third, when physical discomfort, bathroom frequency and anticipatory anxiety all peak simultaneously. Establishing good sleep habits and support early makes the third trimester considerably more manageable.
Does a pregnancy pillow actually help with sleep quality?
For the pain-related causes of pregnancy sleep disruption — hip pain, lower back ache, pelvic pressure — yes, a properly designed pregnancy pillow makes a significant practical difference. It reduces the number of times you wake due to pain and shortens the time to get comfortable when you do. It doesn't address non-physical causes of insomnia, but for the majority of third-trimester sleep complaints, positional support is the most direct intervention available.