In the United States, sudden infant death syndrome (SIDS) continues to be the leading cause of death among babies 12 months and younger.1 Approximately 3,000 infants die each year as a result of SIDS.2
Prior to a national prevention campaign and a major educational push about SIDS prevention, it was common practice to place an infant on his or her stomach or side for sleep. But amid the very effective education to put babies to sleep on their backs, the subject of a prone play position -- tummy time -- is often given cursory attention. Infants who are consistently in a supine position for both sleep and play are at increased risk for delays in gross motor milestones and positional plagiocephaly, a flattening of the occipital area of the skull. Within the first week of life, infants should be placed on their tummy while awake and monitored by an adult. This tummy time provides necessary stimulation, muscle growth and gross motor development.3
The Back to Sleep campaign was introduced in 1994, and SIDS rates have decreased by more than 50% since then.1 However, the latest statistics on the national incidence of SIDS indicate a plateau. As a result, reducing the rate of SIDS was a goal for Healthy People 2010 and continues to be a goal for Healthy People 2020. A literature review performed by Omojokun and Moon4 states that risk factors for SIDS can be separated into three areas: infant characteristics, maternal characteristics and the sleep environment.
Infant risk factors include preterm birth, low birth weight, age of 2 to 4 months, male gender, American Indian or black ethnicity, recent infection, not using a pacifier, and not breastfeeding. Maternal characteristics that contribute to SIDS risk include smoking, young age, lower education, single marital status, low socioeconomic status, higher parity and recent alcohol ingestion. Characteristics of the sleeping environment that contribute to SIDS risk include prone or side sleeping position, soft or excessive bedding, bed sharing or co-sleeping, sleeping on the couch, and overheating.
Since implementation of the Back to Sleep campaign to reduce SIDS, an increase in the incidence of positional plagiocephaly has been documented.5 Positional plagiocephaly results from prolonged placement in the same position. The external pressures created by long-term positioning cause the developing skull to flatten in the occipital area.5 This condition may occur in 1 of every 60 live births,5 a fivefold increase since the early 1990s, when the push for supine sleeping took shape.5 Positional plagiocephaly can be avoided through the introduction of varying play time positions.
Infant sleep position influences early motor development, but its long-term developmental effects are not as clear.6 Supine sleepers often lag behind in milestone achievement when compared to infants placed in other sleeping positions, such as prone or side-lying. This delay does not last longer than a year to 18 months.6 Studies have shown that supine sleepers often have a delay in activities that require the use of upper trunk, upper extremities and shoulder girdle muscles. This includes infant gross motor milestones such as rolling prone to supine, tripod sitting, creeping, crawling and pulling to stand.6 Supine sleeping does not have an effect on fine motor development.6
The Latest Research
Some scientists have suggested that a maldevelopment of the brainstem or delay in brainstem maturation is linked with SIDS. Autopsies of infants who died of SIDS have documented a decrease in serotonin receptor sites within the medulla. Researchers are concerned about this, since the medulla is involved in arousal, thermoregulation, chemosensitivity and blood pressure responses.7 Determination of a possible genetic predisposition related to SIDS is the focus of current and future research.
Another area of concern is the high rate of SIDS among non-Hispanic black, American Indian and Alaska Native infants. Preventing SIDS and promoting health education remain high priorities among these populations.1 Cultural traditions for infant care may play a role in such high rates of SIDS, but this has not been well studied.
According to the American Academy of Pediatrics (AAP),7 the following precautions should be taken to prevent SIDS:
- Place the infant in a supine position for sleep.
- Use a firm sleeping surface.
- Keep all soft objects out of the crib.
- Mother should not smoke during pregnancy.
- Provide a separate infant sleeping area that is near the parents but not in the same bed.
- Allow the baby to use a pacifier while sleeping.
- Avoid overheating in the area where the baby sleeps.
- Avoid commercial devices or home monitors to reduce the risk of SIDS.
- Avoid the development of positional plagiocephaly by implementing tummy time.
- Educate all family members and caregivers in direct contact with the infant about these strategies.
Prone play positioning should begin shortly after birth. Regular periods of tummy time enhance an infant's gross motor skills and upper body strength and reduce the incidence of positional plagiocephaly.3 Research shows that increased tummy time, provided with a supportive and stimulating environment that involves human interaction, results in earlier milestone achievement.6,8-10 NPs and PAs should instruct parents that tummy time should occur whenever the infant is awake and is under direct supervision from a responsible adult. Initially, short periods of 3 to 5 minutes are recommended. The duration should be increased gradually.8 This is an excellent time for parents to have direct interaction with the baby. Initially, a baby is likely to cry, fuss and not tolerate the prone position. With time and repeated daily efforts, a baby will grow to enjoy his or her prone play time.3
Although infants are most at risk for SIDS from 2 to 4 months of age, the risk does not completely resolve after a baby reaches 4 months. This risk continues until the infant is older than 12 months. SIDS education should be presented to parents in a way that facilitates awareness, so as not to scare and overwhelm them. Incorporating daily prone play time several times a day during wake time is as important as supine sleeping.
Evaluation and Surveillance in Practice
Risk factors and red flags for SIDS can be assessed during well baby visits. Building a trusting relationship with the patient's family may aid in this discussion. Providers must be knowledgeable about the risk factors for SIDS and inform parents about them.
Positional plagiocephaly should be identified as soon as possible. Early intervention is crucial, because the skull of an infant grows rapidly during the first year of life.5 At each visit, measure head circumference and evaluate the shape of the head. Typically, positional plagiocephaly can be detected as early as 2 months of age, when the ear migrates anteriorly and the forehead protrudes on the side of the occipital flattening.5 Although positional plagiocephaly is not a life- threatening condition, it may cause long-term facial asymmetry and cosmetic deformities without treatment.5
Gross motor milestone delays related to infant supine positioning should be evaluated at each well baby visit. The Denver Developmental Screening Test and the Denver II are excellent tools for identifying milestone acheivment.6 As mentioned, gross motor skills that involve the upper body may be delayed in supine sleepers. These delays are on the low end of normal, and most infants catch up in their milestone achievement at no later than 18 months.6,9 Reassure parents that supine sleepers eventually attain gross motor milestones with the correct implementation of tummy time.
We must educate all parents about the importance of infant supine sleeping, as well as prone play positioning. Families must be aware of any and all risk factors and developmental issues associated with SIDS and lack of prone play time. Educational pamphlets published by the National Institute of Child Health and Human Development, and Healthy Child Care America are excellent resources that can aid in discussion.8,11 Ongoing education and reinforcement can help further decrease the incidence of SIDS, positional plagiocephaly and gross motor milestone delays.
Sara K. Reinikainen is a family nurse practitioner who works in the urgent care clinic at Lakeview Medical Center in Rice Lake, Wis., and at the Marshfield Clinic Chetek Center in Chetek, Wis.
1. Sudden Infant Death Syndrome (SIDS) and Sudden Unexpected Infant Death (SUID). http://www.cdc.gov/SIDS. Accessed Nov. 18, 2011.
2. Eunice Kennedy Shriver National Institute of Child Health and Development. SIDS Facts. http://www.nichd.nih.gov/sids/upload/PART_II.pdf. Accessed Nov. 21, 2011.
3. Graham JM. Tummy time is important. Clin Pediatr. 2006;45(2):119-121.
4. Omojokun OO, Moon RY. Sudden infant death syndrome: a review of the literature. Curr Pediatr Rev. 2008;4(1):31-39.
5. Biggs WS. Diagnosis and management of positional head deformity. Am Fam Physician. 2003;67(9):1953-1956.
6. Davis BE, et al. Effects of sleep position on infant motor development. Pediatrics. 1998;102(5):1135-1140.
7. American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome. The changing concept of sudden infant death syndrome: diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk. Pediatrics. 2005;116(5):1245-1255. http://aappolicy.aappublications.org/cgi/content/full/pediatrics;116/5/1245. Accessed Nov. 21, 2011.
8. Healthy Child Care America. Back to Sleep, Tummy to Play. [Brochure]. Elk Grove, Ill.: The American Academy of Pediatrics; 2008.
9. Jones MW. Supine and prone infant positioning: a winning combination. J Perin Educ. 2004;13(1):10-20.
10. Pin T, et al. A review of the effects of sleep position, play position, and equipment use on motor development in infants. Dev Med Child Neurol. 2007;49(11):858-867.
11. Safe Sleep for Your Baby. Reduce the risk of Sudden Infant Death Syndrome [Brochure]. Bethesda, Md.: U.S. Department of Health and Human Services, The National Institutes of Health. http://www.nichd.nih.gov/publications/pubs/upload/babiessafesleep-AA.pdf. Accessed Nov. 21, 2011.