How Pregnancy Changes Sleep
Sleep changes in pregnancy are the rule, not the exception. Hormones, a growing uterus, a busier bladder and an active baby all play a part, and each trimester tends to bring its own set of problems. Most are a nuisance rather than a danger. A few, mainly loud snoring, severe restless legs and the position you go to sleep in late in pregnancy, are worth knowing about because something can be done.
This guide walks through the trimesters, then the three sleep disorders that are most common in pregnancy: insomnia, restless legs syndrome and sleep apnea.
First Trimester (Weeks 1 to 12)
Common Sleep Changes
- Strong sleepiness and fatigue. Rising progesterone has a sedating effect, and many women feel drowsy through the day
- Waking to urinate. Hormonal changes and rising blood volume increase urine production even early on
- Nausea, which can strike at night as well as in the morning
- Breast tenderness, which can make some positions uncomfortable
What Helps
- Nap when you can; the fatigue is physiological, not laziness
- Drink plenty during the day and less in the two to three hours before bed
- Keep plain crackers by the bed for night-time nausea
- Go to bed earlier if your body is asking for more sleep
Second Trimester (Weeks 13 to 27)
Common Sleep Changes
- More energy. Many women feel noticeably better
- Leg cramps, painful tightening of the calf at night
- Heartburn, as the growing uterus presses on the stomach
- Nasal congestion, from extra blood volume swelling the lining of the nose, which can also bring on snoring
- Vivid dreams, partly because more awakenings mean more dreams are remembered
What Helps
- Raise the head of the bed or add a pillow to ease heartburn, and avoid large late meals
- Stretch your calves before bed to reduce cramps
- A saline nasal spray or rinse can ease congestion
- Start practicing going to sleep on your side, so it is a habit by the third trimester
Third Trimester (Weeks 28 to 40)
Common Sleep Changes
- Hard to get comfortable as the baby grows
- Frequent urination returns as the baby presses on the bladder
- Back and hip pain from the extra weight and loosened ligaments
- Shortness of breath as the uterus pushes up on the diaphragm
- Restless legs, most common now (see below)
- Contractions and fetal movement, which can wake you through the night
What Helps
- A pregnancy pillow (full-length or wedge) to support your belly, back and hips
- A pillow between your knees to keep the hips aligned and ease back pain
- Go to sleep on your side, left or right (see the next section)
- Gentle stretching or prenatal yoga before bed
Sleep Position After 28 Weeks
The position you go to sleep in matters in late pregnancy. When you lie on your back, the weight of the uterus can press on the large blood vessels that run along the spine and reduce blood flow to the baby.
A large analysis that pooled the original data from several studies found that, from 28 weeks of pregnancy, going to sleep on the back was linked to roughly two and a half times the risk of late stillbirth compared with going to sleep on the left side. Going to sleep on the right side carried similar risk to the left. Stillbirth is uncommon, and the researchers estimated that settling to sleep on the side could prevent about 6% of late stillbirths.
What this means in practice:
- From 28 weeks, settle to sleep on either side. Left and right are both fine; choose the more comfortable one
- Waking on your back is common and not a reason to panic. The studies looked at the position you go to sleep in. If you wake on your back, roll onto your side
- Use the same side-sleeping habit for naps and when going back to sleep after a night waking
- A pillow behind your back can make it harder to roll over
Sleep Disorders During Pregnancy
Insomnia
Trouble falling or staying asleep is common in pregnancy. A meta-analysis of studies from around the world found insomnia symptoms in about 38% of pregnant women overall, rising from about 1 in 4 in the first trimester to about 40% in the third. Discomfort, needing to urinate, heartburn and worry about labor and parenthood all contribute.
What helps:
- A steady wake-up time, a wind-down routine and the bedroom basics in Sleep Hygiene: A Complete Guide
- If you have been awake about 20 minutes, get up and do something quiet in dim light until you feel sleepy, rather than lying in bed frustrated (stimulus control)
- For insomnia that lasts, cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment and needs no medication. The sleep restriction part should be adapted and supervised in pregnancy rather than done alone
- Discuss any sleep medication, including over-the-counter sleep aids, with your obstetric provider before taking it
Restless Legs Syndrome
Restless legs syndrome (RLS) is an uncomfortable urge to move the legs that comes on at rest, gets worse in the evening, and eases with movement. It is one of the most common sleep problems of pregnancy. A meta-analysis of more than 50,000 pregnant women found RLS in about 1 in 5 across pregnancy: about 8% in the first trimester, 16% in the second and 22% in the third. After delivery, the figure fell to about 4%, so for most women it goes away once the baby is born.
Iron matters. Low iron is a common contributor, and pregnancy uses a great deal of it. The International RLS Study Group's guideline for pregnancy and breastfeeding sets out the case for iron supplementation, and the 2025 AASM guideline asks that iron be checked in everyone with significant RLS. The levels that matter for RLS are higher than the ones used to diagnose anemia; The Role of Iron in Restless Legs Syndrome explains why.
What helps:
- Ask your provider to check ferritin, the body's iron store
- Iron supplements if your levels are low, as directed by your provider
- Moderate daytime activity, and walking, stretching or massaging the legs in the evening
- Avoid triggers: caffeine, alcohol, and sedating antihistamines such as diphenhydramine (Benadryl), which is in many "PM" sleep aids and some anti-nausea combinations
- The 2025 AASM guideline asks prescribers to weigh each RLS medicine's safety in pregnancy. Most women manage with iron and the measures above; for severe symptoms, the choice of medicine is made case by case with your obstetric provider and a sleep specialist
Snoring and Obstructive Sleep Apnea
In obstructive sleep apnea, the throat repeatedly narrows or closes during sleep, lowering oxygen levels and waking the brain many times a night. Weight gain, fluid shifts and nasal congestion all make it more likely as pregnancy goes on.
In a large U.S. study of women in their first pregnancy, home sleep testing found sleep-disordered breathing in about 4% in early pregnancy and 8% by mid-pregnancy. Women who had it were about twice as likely to develop preeclampsia and two to three times as likely to develop gestational diabetes, even after adjusting for other risk factors.
Tell your provider if you have:
- Loud snoring, especially if it is new or getting worse
- Pauses in breathing, choking or gasping that a partner notices
- Strong daytime sleepiness that goes beyond ordinary pregnancy tiredness
- High blood pressure or gestational diabetes together with any of the above
Sleep apnea can be tested for during pregnancy, and treatment with CPAP, which stands for continuous positive airway pressure, is considered safe in pregnancy. See Understanding Your Sleep Study for what testing involves.
After the Baby Arrives
Restless legs and pregnancy-related snoring often settle after delivery, though sleep is broken in new ways by night feeds. If loud snoring, restless legs or insomnia continue well after the birth, they deserve their own evaluation rather than being put down to a new baby. Low mood, anxiety or trouble sleeping even when the baby is asleep are worth raising with your provider promptly.
When to Contact Your Provider
Speak with your obstetrician or midwife if you have:
- Loud snoring or witnessed pauses in breathing during sleep
- Daytime sleepiness that interferes with daily life or driving
- Restless legs that regularly keep you from sleeping
- Insomnia that does not improve with the steps above
- Significant changes in mood, anxiety or depression affecting sleep
Key Takeaways
- Sleep changes in pregnancy are common, and most improve after delivery
- From 28 weeks, go to sleep on your side; left and right are both fine, and waking on your back is not a reason to panic
- About 38% of pregnant women have insomnia symptoms; CBT-I treats insomnia without medication
- About 1 in 5 pregnant women have restless legs, most in the third trimester; ask for an iron check
- Loud snoring, breathing pauses or marked sleepiness can mean sleep apnea, which is linked to preeclampsia and gestational diabetes, so mention them to your provider