Pre-emptive positioning: SIDS then and now

By Dr. Denis Leduc

Shortly after beginning my career as a community paediatrician in Montreal and forming the Association of Community-based Paediatricians of the Montreal Children’s Hospital, I was involved in my first infant death from SIDS. I was devastated by this event, and overcome by the loss the parents suffered.

Those parents channeled their grief into the Jeremy Rill Centre, which they created to support and help parents dealing with the shock of losing a child.

That was in 1986. What have we learned since then?

In 1993, a joint statement by the CPS, Canadian Institute of Child Health, Health Canada, and Baby’s Breath provided the first national and evidence-based guidance on the known risk factors for SIDS.

At that time, it was clear that sleeping supine was protective, but side-sleeping was not established as a risk factor. The relationship between breastfeeding (protective) and SIDS was unclear and there was insufficient data to make recommendations on sharing a room or sharing a bed with the baby.

Since then, we have achieved major insights into the epidemiology of SIDS, and the joint statement was updated each time a change to recommendations was required. A “Back to Sleep” public education campaign was launched in 1999.

The most recent iteration of the joint statement was published in 2021. It reflects the most recent literature and has an extensive list of references. The statement describes the most important modifiable factors that can lower the risk of SIDS:

• Placing infants on their backs to sleep for every sleep;
• Protecting infants from exposure to tobacco smoke, before and after birth;
• A safe sleep environment for infants. The safest place for an infant to sleep is in a crib, cradle, or bassinet that meets current Canadian regulations (free of soft loose bedding, bumper pads, toys and sleep/head positioners) placed in the parent’s room for the first 6 months (room sharing).
• Breastfeeding for at least 2 months, with greater protection provided with longer duration.
• Practising the principles of safe sleep for every sleep, at home, in child care settings, and when travelling.

The statement also describes modifiable risk factors that can increase the risk of SIDS:

• Bedsharing, where an infant shares a sleeping surface (such as an adult bed, sofa, or armchair) with a parent, caregiver, or sibling. Infants less than 4 months old are at particularly high risk for SIDS in this sleeping arrangement.
• Infant sleep products that attach to the adult bed.

The rate of SIDS in Canada decreased by 50% between 1999 and 2004, attributable mainly to the Back to Sleep campaign. Since then, however, rates of SIDS have not improved significantly. Why not?

It is important to remember that the cause(s) of SIDS has not been established and that risk factors are not causes.

Expertise in research have focused on target genes that relate to epilepsy and channelopathies.

After a thorough investigation, including autopsy, a significant proportion of sudden unexpected infant deaths have been attributed to infection, cardiopathy, immune defects, brain malformations and other pathologies.

A recent publication by Statistics Canada has evaluated the circumstances of sudden and unexpected sleep-related infant deaths, drawn from coroner and medical examiner databases. Six hundred and sixty closed cases occurring between 2015 and 2019 across Canada (except Manitoba) were analyzed and reviewed. For the provinces and territories included, data are not available for all years.

What does the StatsCan document add to our understanding of SIDS?

Thanks to the reviews and evaluations of each case by Canadian coroners and medical examiners, we are able to confirm the principles in the joint statement:

• The majority (70%) of sudden and unexpected sleep-related deaths occurred in infants under 4 months of age.
• More than 9 in 10 (92%) infants who died suddenly in their sleep were in an unsafe sleeping environment. In the other 8%, the risk factor information was unspecified. In 75%, at least two risk factors were present.
• Nearly 7 in 10 sudden and unexpected sleep-related deaths (69%) occurred on a surface not intended for infant sleep.
• Over half of infants who died suddenly in their sleep (53%) were sharing a bed with one or more people. Note that the Canadian Community Health Survey (2015/16) found that “one-third of mothers indicated their last child shared a bed with them or anyone else, every day or almost every day, when the child was under 12 months of age”. 
•  In 33% of sudden sleep-related deaths, the infant was found on their side or stomach.
• Exposure to tobacco smoke was reported in more than 1 in 6 (18%) of sudden and unexpected sleep-related infant deaths.

Can these “updates” help us formulate our current recommendations to maximize the efficacy of our SIDS prevention advice?

Because of the continuing uncertainty about the pathogenesis of this “syndrome”, the clinical focus continues to target modifiable risk factors: I believe that we can make a difference if we prioritize SIDS prevention messages and include them at every encounter in the first 4 months of life, which is when 70% of sleep-related deaths occur. Here are three key messages for parents and caregivers:

1. Safe sleeping surfaces for baby are critically important.
2. Do not bedshare, even if breastfeeding.
3.  Always put baby to sleep on their back, for all sleeps.

Our significant progress in understanding some of the most important and critical factors associated with risk for SIDS must now be used to develop and implement targeted, evidence-based strategies to protect these vulnerable infants.

Delivering these life-saving messages to parents is our only hope of translating research into effective practice.

Dr. Denis Leduc is a past president of the CPS, co-author of the Rourke Baby Record, and editor of Well Beings: A Guide to Health in Child Care. He is a recently retired community paediatrician and associate professor of paediatrics at the McGill University Health Centre in Montreal, Quebec.

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