Sleep During Pregnancy: Why It Gets Harder and What Actually Helps

Sleep deteriorates during pregnancy because of a collision of physical discomfort, hormonal changes, anxiety, and the growing demands on your body — and it gets progressively worse, with the third trimester being the most severely affected. Up to 78% of pregnant women report disturbed sleep, and up to 64% meet the criteria for clinical insomnia in the third trimester.

This is not a minor inconvenience, and it is not "just practice for when the baby arrives" (one of the least helpful things anyone can say to a pregnant person who cannot sleep). Pregnancy insomnia is a real condition with real consequences for mood, coping, and — according to research — even birth outcomes.

Understanding why it is happening can take away some of the frustration, even if it cannot take away the discomfort.

Physical causes:

• Difficulty finding a comfortable position. The growing uterus places pressure on the diaphragm (making breathing feel effortful), the bladder (causing frequent urination), and the lower back (causing pain). Hip pain, pelvic girdle pain, and heartburn all worsen in the third trimester.
• Frequent urination. Most pregnant women wake two to four times per night to use the toilet in the third trimester. Reducing fluids in the evening helps slightly, but dehydration carries its own risks.
• Restless Legs Syndrome (RLS). Affecting approximately 26% of pregnant women in the third trimester, RLS causes an irresistible urge to move the legs, often with uncomfortable crawling or tingling sensations that worsen at rest. It is often linked to iron deficiency. If you are experiencing this, speak to your midwife — it is a medical issue, not something to manage alone.
• Leg cramps. Sudden, painful cramping in the calves or feet, often at night. Stretching before bed and staying hydrated may help.
• Heartburn. The growing uterus pushes the stomach upward, and progesterone relaxes the valve between the stomach and oesophagus. Sleeping slightly elevated can help.

Psychological causes:

• Anxiety about birth and parenting. Worry about labour, complications, and the unknown is extremely common. First-time parents may experience anticipatory anxiety about caring for a newborn.
• Vivid dreams and nightmares. Extraordinarily common in pregnancy, driven by hormonal changes, more frequent waking (which means more dream recall), and the psychological processing of impending parenthood.
• Sleep pressure. "I must sleep now because I won't get any sleep once the baby comes" creates a paradox: the pressure to sleep makes sleep harder.

If any of these symptoms are persistent or significantly affecting your daily functioning, speak to your midwife or GP. This is not something you need to endure in silence.

From 28 weeks, Tommy's (the UK's leading stillbirth charity) recommends going to sleep on your side — either side, though the left is commonly preferred as it optimises blood flow to the placenta. Going to sleep on your back in the third trimester was associated with a 2.3-fold increase in late stillbirth risk in the landmark MiNESS study.

Important context:

• The advice relates to the position in which you fall asleep — the position you spend most of the night in. If you wake up on your back, do not panic. Simply roll onto your side.
• The risk is thought to relate to the weight of the uterus compressing the inferior vena cava (the major vein returning blood to the heart), which can reduce blood flow to the baby.
• Either side is safe. Left side is commonly recommended because it optimises blood flow, but sleeping on your right side is also fine.

Practical tips for staying on your side:

• Use pillows strategically: between your knees, under your bump, behind your back. A pregnancy pillow (U-shaped or C-shaped) can help maintain side-lying position throughout the night.
• If you find yourself rolling onto your back, a pillow behind your back can act as a gentle barrier.
• Some people find sleeping slightly propped up (rather than flat) helps both with breathing and with staying off their back.

This is Tommy's guidance, backed by robust research. For the full evidence, visit the Tommy's Sleep On Side campaign at tommys.org/sleeponside, or speak to your midwife.

While you cannot eliminate the physical discomfort of late pregnancy, there are evidence-based strategies that can genuinely improve sleep quality. The most effective single intervention is maintaining a consistent wake time, even after a bad night.

Sleep hygiene adapted for pregnancy:

• Consistent wake time. Even when tempted to lie in after a terrible night, getting up at the same time each morning anchors your circadian rhythm and builds sleep pressure for the following night. This is the single most effective behavioural intervention for insomnia.
• Keep the bedroom cool, dark, and quiet. 16 to 18 degrees Celsius is ideal for sleep during pregnancy.
• Remove screens from the bedroom or use blue light filters in the evening. Scrolling in bed trains your brain to associate bed with wakefulness.
• Use the bed only for sleep (and rest). If you are lying awake for more than 20 to 30 minutes, get up, go to another room, do something calm — reading, gentle stretching, breathing exercises — and return to bed when drowsy. This prevents the bed from becoming associated with frustration.
• Avoid heavy meals close to bedtime (helps with heartburn). Elevate the head of the bed slightly if reflux is an issue.
• Gentle exercise during the day — walking, swimming, prenatal yoga — but not in the two hours before bed.

Managing anxiety about sleep:

• Cognitive Behavioural Therapy for Insomnia (CBT-I) is the gold-standard treatment for insomnia and is safe in pregnancy. Some NHS Trusts offer it via the Improving Access to Psychological Therapies (IAPT) programme — it is worth asking your GP.
• Mindfulness and relaxation techniques can reduce the pre-sleep arousal that keeps you awake. The NHS Every Mind Matters tools are freely available.
• "Sleep effort" — trying too hard to sleep — is paradoxically one of the biggest drivers of insomnia. Letting go of the need to sleep perfectly is therapeutic in itself.

Napping: Short afternoon naps of 20 to 30 minutes are fine and can help manage daytime fatigue. Avoid napping after 15:00, as late naps can reduce sleep pressure for the night ahead.

Yes. Research consistently shows that pregnancy insomnia is a significant predictor of both postnatal insomnia and postnatal depression. The sleep problems that begin in the third trimester often do not resolve after birth — they are compounded by the demands of a newborn.

This is not said to create fear. It is said because addressing pregnancy sleep problems proactively — before birth — can make a real difference to how you cope in the postnatal period.

Key findings from the research:

• Poor maternal sleep during pregnancy is associated with longer labour, higher rates of Caesarean section, and increased risk of pre-eclampsia (Okun et al., 2011)
• Women who experience insomnia in pregnancy are more likely to experience insomnia postnatally, independent of the baby's sleep patterns (Dorheim et al., 2014)
• Pregnancy insomnia is associated with increased risk of preterm birth in severe cases (Li et al., 2020)

How to frame this for yourself: Not as a threat ("If I don't sleep, bad things will happen" — this is exactly the kind of thinking that makes insomnia worse), but as motivation to take your sleep seriously and seek help if you need it. Investing in your sleep now is one of the kindest things you can do for yourself and your baby.

When to seek help:

• If insomnia is persistent — more than three nights per week for more than three weeks
• If your mood is significantly affected: persistent low mood, hopelessness, excessive worry, inability to enjoy anything
• If you feel unable to cope or function during the day

Your midwife, GP, or NHS 111 are the appropriate starting points. If you are concerned about your mental health during pregnancy, please speak to your healthcare provider. This is not something to manage alone.

Vivid, strange, or disturbing dreams are extremely common during pregnancy, particularly in the third trimester. You are not losing your mind — this is a well-documented phenomenon driven by hormonal changes, more frequent waking, and the psychological processing of a major life transition.

Why it happens:

• Hormonal changes. Increased progesterone and oestrogen affect the quality and content of dreams. Progesterone in particular has been linked to more vivid dream recall.
• More frequent waking. Because you are waking more often during the night (to use the toilet, reposition, or because of discomfort), you are more likely to wake during or immediately after a dream — which means you remember more of them. In normal sleep, most dreams are forgotten because we do not wake during them.
• Psychological processing. Your brain is processing an enormous amount of emotional material: excitement, anxiety, identity shifts, relationship changes, and the anticipation of parenthood. Dreams are one of the ways your brain works through this.

Dreams about the baby, about birth, about things going wrong, about forgetting the baby in unusual locations — all are normal. They do not mean something is wrong, and they are not predictions.

If nightmares are causing significant distress or fear of going to sleep, mention it to your midwife. In most cases, vivid pregnancy dreams are harmless and temporary — they are your brain's way of processing one of the biggest transitions of your life.

No — not in the biological sense. Sleep cannot be stored like money in a bank. Your brain does not accumulate a surplus of rest that can be drawn down later. This is one of the most common pieces of advice expectant parents receive, and it is physiologically incorrect.

However — and this is an important however — going into birth well-rested rather than already sleep-deprived from untreated pregnancy insomnia does make a genuine difference. Research shows better coping, faster recovery, improved mood, and greater resilience in the early postnatal weeks for parents who were sleeping reasonably well before birth compared to those who were already in significant sleep debt.

So the advice is not to "bank sleep" but to take your current sleep seriously:

• If you are struggling with insomnia, seek help now — not after the baby arrives
• Establish good sleep hygiene habits (consistent wake time, dark bedroom, no screens before bed) that will carry over into the postnatal period
• Plan your night-time support strategy with your partner while you are both rested and thinking clearly
• Set realistic expectations for the first weeks — understanding what newborn sleep actually looks like reduces the shock when it arrives
• Rest when you can. Nap if your body wants to nap. Lower your standards for everything that is not essential. Your sleep matters.

If you are in your third trimester and sleep has become genuinely difficult, you are not alone — the majority of pregnant women experience this. But it does not have to be accepted in silence. Your midwife and GP can help, and addressing it now sets you up better for the postnatal period.

If sleep disruption is significantly affecting your daily life, your mood, or your ability to function, it is worth raising with your midwife or GP. Pregnancy sleep problems are often dismissed as "normal" — and while disrupted sleep is common in pregnancy, clinical insomnia that impairs your wellbeing deserves attention and treatment.

Speak to your healthcare provider if:

• You are unable to fall asleep or stay asleep more than three nights per week for more than three weeks
• You have restless legs that are preventing you from settling at night — this may be linked to iron deficiency and is treatable
• You or your partner have noticed snoring, gasping, or pauses in breathing during sleep — this could indicate sleep-disordered breathing
• Your mood is persistently low, anxious, or hopeless — pregnancy insomnia is a predictor of postnatal depression, and early intervention makes a difference
• You are so tired during the day that you feel unsafe (driving, for example)
• You are having thoughts of harming yourself — contact your midwife, GP, or call the Samaritans on 116 123 immediately

Sleep during pregnancy is not a luxury. It is a health priority. You deserve to be taken seriously, and there are evidence-based treatments available — including CBT-I, which is safe in pregnancy and available through some NHS pathways.

This is sleep support, not medical advice. If you are concerned about your health during pregnancy, please speak to your midwife, GP, or call NHS 111.