A new Swedish study has put safe infant sleep back in the headlines. The findings are serious but the risk is small, and the practical advice for parents is clear, calm and easy to follow. Here is what the research shows and what Swedish health authorities recommend.
In July 2026, researchers at Karolinska Institutet published the largest Swedish study yet on sudden unexpected postnatal collapse, or SUPC. It is worth saying at the outset that this is rare. The study, published in the journal Acta Paediatrica, found 149 cases among roughly 483,000 births in Stockholm County over two decades, which works out to about 31 cases per 100,000 live births. Across Sweden that is around thirty affected infants a year, of whom two to four die. The point of the research is not to frighten new parents but to show that most of these events are preventable with a few simple habits.
What the study found
Sudden unexpected postnatal collapse is when an apparently healthy newborn suddenly stops breathing and collapses during the first days of life. The Karolinska team, led by paediatrician and professor Eric Herlenius, looked at cases from seven Stockholm maternity units between 2002 and 2022. Two patterns stood out.
The first is timing. Around 81 per cent of collapses happened within the first 24 hours after birth, and half within the first four hours. This is the window when a newborn is still adjusting to breathing on its own, and it is why Swedish maternity wards keep a close eye on mother and baby in those early hours.
The second is position and closeness during sleep. Two thirds of the cases happened while the baby was sharing a bed with a parent, and a further share occurred during unsupervised skin-to-skin contact when an adult had fallen asleep. In many cases the baby was found face down with its airway blocked. The outcomes can be grave, with about 7 per cent of affected infants dying and roughly a quarter left with lasting neurological injury, which is exactly why the prevention message matters.
It is important not to confuse SUPC with sudden infant death syndrome, known in Swedish as plötslig spädbarnsdöd. SUPC happens in the very first days, often in hospital, while sudden infant death typically occurs later in the first months at home. The reassuring part is that the same safe-sleep habits protect against both.
The Swedish safe-sleep advice
Sweden’s guidance is set by the National Board of Health and Welfare, Socialstyrelsen, and explained for parents on the national health guide 1177. It comes down to six simple points.
- Put your baby to sleep on the back. The risk drops when a baby sleeps on its back rather than on its front or side. This single habit is the most important of all.
- Give your baby its own sleep space. 1177 advises that babies under three months sleep most safely in their own cot. Room-sharing is fine and often practical, but the baby has its own flat, firm surface.
- Keep the air nicotine free. Smoking and nicotine during pregnancy and around the baby raise the risk, so a completely smoke-free home matters.
- Do not let your baby get too warm. Aim for comfortably warm, not hot, and make sure the face is uncovered and the baby can move freely.
- Breastfeed if you can. Breastfeeding offers some protection, in part because breast milk helps guard against infection.
- A dummy at sleep time can help. Using a pacifier when settling to sleep is linked to a lower risk.
Skin-to-skin and bed-sharing in practice
Skin-to-skin contact is genuinely good for newborns, and Swedish care encourages it warmly. The study does not argue against it. It argues for doing it safely. As Eric Herlenius has explained, skin-to-skin contact is important for newborns, but parents need to make sure the baby’s airway stays clear and visible. His practical advice is direct: adults should not fall asleep while holding their baby against the chest, and infants should not share a bed with their parents during the first three months of life.
For tired new parents, and especially in the first exhausting nights, the safest routine is to enjoy plenty of skin-to-skin while awake and alert, then move the baby onto its back in its own cot for sleep. If you feel yourself drifting off during a night feed, it is safer to place the baby down first.
What this means for you
None of this needs to make the newborn weeks anxious. The chance of a collapse is small, and the habits that reduce it are the same gentle routines that midwives and child health nurses in Sweden already teach. Back to sleep, own cot, a clear and cool sleep space, and no falling asleep together in the early months. That is most of it.
Your BVC child health centre is the natural place to raise any worries, and the nurses there are used to explaining safe sleep to first-time parents from every background. Once your baby grows into a toddler, sleep becomes less about safety and more about routine, and our guide to building a calm bedtime takes it from there.
Where to get advice in English
If you would like to talk it through, you can call 1177 for health advice, which is available in English, or raise it at your next BVC visit. Trust the official Swedish guidance over anything you read in a parenting forum, and when in doubt, ask a professional. A short conversation with your child health nurse is worth more than a long night of worry.
Senast faktagranskad: 17 juli 2026