Tag: United States

Statistics of SIDS incidences

SIDS in time

Overall statistics of SIDS incidences show that number of sudden deaths of infants declines. However, the biggest decrease we have seen in 90s – the result of the “Back to sleep” campaign. Since then, the decrease is much smaller, almost insignificant.

Sudden Infant Death Syndrome (SIDS) rates declined considerably from 130.3 deaths per 100,000 live births in 1990 to 55.7 deaths per 100,000 live births in 2001. Unknown Cause infant mortality rates have remained unchanged from 1990 to 2010. In 2011, the Unknown Cause mortality rate in infants was 22 deaths per 100,000 live births. Accidental Suffocation and Strangulation in Bed (ASSB) mortality rates remained unchanged until the late 1990s. Rates started to increase beginning in 1998 and reached the highest rate at 17.8 deaths per 100,000 live births in 2008. The total combined Sudden Unexpected Infant Death rate (which includes SIDS, Unknown Cause, and ASSB) declined considerably following the American Academy of Pediatrics safe sleep recommendations released in 1992 the initiation of the Back to Sleep campaign in 1994, and the release of the Sudden Unexplained Infant Death Investigation Reporting Form in 1996. However, the total combined Sudden Unexpected Infant Death rate has not decreased significantly since 1999.

Sudden Infant Death Syndrome (SIDS) rates declined considerably from 130.3 deaths per 100,000 live births in 1990 to 55.7 deaths per 100,000 live births in 2001.
Unknown Cause infant mortality rates have remained unchanged from 1990 to 2010. In 2011, the Unknown Cause mortality rate in infants was 22 deaths per 100,000 live births.
Accidental Suffocation and Strangulation in Bed (ASSB) mortality rates remained unchanged until the late 1990s. Rates started to increase beginning in 1998 and reached the highest rate at 17.8 deaths per 100,000 live births in 2008.The total combined Sudden Unexpected Infant Death rate (which includes SIDS, Unknown Cause, and ASSB) declined considerably following the American Academy of Pediatrics safe sleep recommendations released in 1992 the initiation of the Back to Sleep campaign in 1994, and the release of the Sudden Unexplained Infant Death Investigation Reporting Form in 1996. However, the total combined Sudden Unexpected Infant Death rate has not decreased significantly since 1999.

SIDS per infant group

Sudden infant death syndrome happens from one every 200 births to one every 20000 births. There are several factors that increase the SIDS risk in certain groups of infants:

  1. Gestation age (data for US, in late 90s)
    • at 37–39 weeks of gestation SIDS rate was 0.73/1000
    • at 28–31 weeks of gestation SIDS rate was 2.39/1000
  2. Birth weight (related to gestation age, data for US, late 90s):
    • for infants weighing 1000–1499 g SIDS rate was 2.89/1000
    • for infants weighing 3500–3999 g SIDS rate was only 0.51/1000.
  3. Race/culture (see our explanation of genetics of SIDS, data for US, 2010-2013):
    • for American Indian infants SIDS rate was 0.9/1000
    • for Non-Hispanic Black infants SIDS rate was 0.8/1000
    • for Non-Hispanic White infants SIDS rate was 0.4/1000
    • for Hispanic infants SIDS rate was 0.3/1000
    • for Asian/Pacific Islander infants SIDS rate was 0.2/1000

Comparing SIDS rates to infant mortality rates

Sudden infant death syndrome is not the only reason of infants’ deaths in the world. It is assumed that across the world, the leading causes of premature infant deaths were birth asphyxia, pneumonia, pre-term birth complications, neonatal infection, diarrhoea, malaria, measles and malnutrition. However, when only first world countries are taken into account, some research suggests SIDS is the third the most leading cause of infant mortality. Let’s compare the two rates in United Kingdom and United States:

  1. In UK overall SIDS rate is 0.2/1000, but it’s five times higher when mother is younger than 20. Infant mortality rate there is 4.19/1000, so SIDS is the cause of 5% of premature deaths of infants.
  2. In US overall SIDS rate (averaged across all groups) is 0.5/1000. Infant mortality rate is 5.97, so SIDS is the cause of 8% of premature deaths of infants.

The numbers are pretty similar and in both countries SIDS accounts for less than 10% of all premature deaths.

 

How is vaccination related to sudden infant death?

Fear of vaccination is quite wide spread. Vaccines are linked (albeit research does not support this link) to autism, but they were some time ago also linked to SIDS incidences. Are vaccines safe to your child? It turns out that yes, they are, and careful research ruled out immunization as a possible cause of sudden infant death syndrome. Even more, vaccines were thought to lower the risk of SIDS:

Immunisations are associated with a halving of the risk of SIDS. There are biological reasons why this association may be causal, but other factors, such as the healthy vaccinee effect, may be important. Immunisations should be part of the SIDS prevention campaigns. [Vennemann et alo, 2007]

This is related to currently prevailing hypothesis about SIDS causes. Paul Goldwater published w 2011 a review on SIDS (Goldwater, 2011) in which he assessed all the hypotheses of SIDS mechanism according to three questions:

  1. Does the hypothesis take into account the key pathological findings in SIDS?
  2. Is the hypothesis congruent with the key epidemiological risk factors?
  3. Does it link 1 and 2?

Some hypotheses did not meet any the criteria and only one (infection) met all three. That might explain apparent lower ratio of SIDS incidences in vaccinated children – stronger immune system might extert protective effect on an infant. This link is putatively confirmed in the 2015 study by German researchers who studied specifically  diphtheria-tetanus-pertussis immunization and its putative role in SIDS:

Increased DTP immunisation coverage is associated with decreased SIDS mortality. Current recommendations on timely DTP immunisation should be emphasised to prevent not only specific infectious diseases but also potentially SIDS. [Müller-Nordhorn et al, 2015]

Other studies claim that this is not the case, as no correlation between vaccination and sudden infant death was observed after correcting for confounding variables:

There is no increased or reduced risk of sudden infant death during the period after the vaccination. The previously reported protective effect seen in case contol studies is based on the inclusion of unvaccinated cases.  [Kuhnert et al, 2012]

Whatever hypothesis about protective (or lack of protective) effect is true, it is absolutely clear that vaccines do not cause SIDS. Having your child immunized will protect it from other diseases, but will not have a negative effect when sudden death is concerned.

Safe Sleep for Your Baby video

 

The Safe Sleep for Your Baby video provides steps to create a safe sleep environment for your baby and lower the risk of Sudden Infant Death Syndrome, or SIDS.

Transcript – Safe Sleep for Your Baby video

Is there anything more peaceful than a sleeping baby?

Creating a safe sleep environment will help your baby sleep safely and lower the risk of Sudden Infant Death Syndrome, commonly known as SIDS.

There are steps that you can take to create a safe sleep environment for your baby and lower the risk of SIDS.

Provide a smoke-free environment before and after your baby is born. One-third of all SIDS deaths could be prevented if pregnant women did not smoke. Second-hand smoke also increases the risk of SIDS, after your baby is born.

Always place your baby on his or her back to sleep, at naptime and night time. Babies who always sleep on their backs have a lower risk of SIDS. Placing your baby on his or her back to sleep works. The rate of SIDS has dropped by more than half since the 1999 Back to Sleep campaign.

Provide your baby with a safe sleep environment that has a firm surface and no pillows, comforters, quilts or bumper pads. The safest place for your baby to sleep is in a crib, cradle or bassinet that meets Canadian safety regulations.

Place your baby to sleep in a crib, cradle or bassinet next to your bed. Room sharing for the first 6 months lowers the risk of SIDS and helps your baby sleep safely.

Breastfeeding can protect your baby. Any amount for any duration offers protection; but exclusive breastfeeding for the first 6 months can lower the risk of SIDS by up to 50%.

Parents and all caregivers can create a safe sleep environment at home, in childcare settings and when travelling.

Remember these steps to create a safe sleep environment for your baby and lower the risk of SIDS.

Provide a smoke-free environment before and after your baby is born.

Always place your baby on his or her back to sleep, at naptime and night time.

Provide your baby with a safe sleep environment that has a firm surface and no pillows, comforters, quilts or bumper pads.

Place your baby to sleep in a crib, cradle or bassinet next to your bed.

Breastfeeding can protect your baby.

The Safe Sleep for Your Baby brochure is available from the Public Health Agency of Canada.

 

 

What is SIDS

CC-BY Daniel Rothamel
CC-BY Daniel Rothamel

Sudden Infant Death Syndrome (SIDS) is a sudden and unexpected death of an infant of age below 12 months (the maximum of SIDS incidences occurs between 2nd and 4th months of child’s age). SIDS is the most common cause of infants’ deaths in first world countries and occurs roughly once per 10000-20000 births.

SIDS is a complex syndrome and it is assumed to be a result of endogenous and exogenous factors (Trachtenberg et al, 2012). It is diagnosed by exclusion – all other causes of infant’s death are excluded systematically according to a special protocol. As we gather more knowledge about diseases and syndromes of young age, the protocol is systematically updated (one of the latest updates are covered by Jensen et al, 2012). The most common SIDS risk factors are: male gender, low birth weight, improper sleep position, tobacco smoke exposition, infection, heat stress or co-sleeping with parents. However, these risk factors cover so many infants, that they cannot be used to predict the risk of SIDS incidence.

For some time it was popular to use home cardiomonitors or respiratory monitors, but quickly it was shown that sleep apnea happens to perfectly healthy children. In a large research on effectiveness of home cardiomonitors it was shown that these apparatuses alarmed parents of more than 40% of monitored infants (Ramanathan R et al, 2001), which means their specificity was three orders of magnitude below level of SIDS occurences (40% vs less than 0.1%). Current guidelines do not recommend using home cardiomonitors and respiratory monitors as a means of preventing SIDS (AAP, 2011), unless there is a recommendation from a physician.

The only major effect so far of SIDS research was a campaign „Back to Sleep” that ran in early nineties. Parents were advised to put their babies to sleep on their back. These recommendations are thought to be responsible to lower the number of SIDS incidences by 50% after 1990 (Ponsonby et al, 2002).. However, since then, the statistics of sudden infrant death syndrome did not improve (Trachtenberg et al, 2012) – according to CDC, in the US only, there are 2500 SIDS incidences per year.

Despite over 10 thousands of research papers on the topic (according to PubMed database), SIDS mechanism is still a mystery. Other than general recommendations for parents and day-care units, there is no diagnostic procedure that would help in assessing the risk of sudden infant death syndrome.

References:

AAP (2011) SIDS and Other Sleep-Related Infant Deaths: Expansion of Recommendations for a Safe Infant Sleeping Environment. Pediatrics: peds.2011–2284

Jensen LL, Rohde MC, Banner J & Byard RW (2012) Reclassification of SIDS cases—a need for adjustment of the San Diego classification? Int. J. Legal Med. 126: 271–277

Ponsonby A-L, Dwyer T & Cochrane J (2002) Population trends in sudden infant death syndrome. Semin. Perinatol. 26: 296–305

Ramanathan R, Corwin MJ, Hunt CE & et al (2001) Cardiorespiratory events recorded on home monitors: Comparison of healthy infants with those at increased risk for sids. JAMA 285: 2199–2207

Trachtenberg FL, Haas EA, Kinney HC, Stanley C & Krous HF (2012) Risk factor changes for sudden infant death syndrome after initiation of Back-to-Sleep campaign. Pediatrics 129: 630–638