All three of my kids were swaddled as newborns in the hospital — as are 90 percent of babies in the United States. The cocoon-like wrapping purportedly keeps babies from jerking awake when they thrash out their arms and legs in a startle reflex.
But my husband and I could never master the wrap at home. Our babies would kick the blanket and come unbound.
As it turns out, that may have been a good thing. A provocative review of recent studies published last week in the British journal Archives of Disease in Childhood found that while swaddling does help infants sleep better at night and might soothe colic symptoms, it could raise the risk of problems later in life that necessitate hip replacements by middle age.
That’s because infants are usually swaddled with their legs extended straight; if the blankets are wrapped too tightly for babies to bend their legs, their hips could receive too much pressure over time, causing an abnormal formation of the hip socket called dysplasia.
“The babies’ legs should not be tightly wrapped in extension and pressed together,” wrote the article author Dr. Nicholas Clarke, an orthopedic surgeon at the University Hospital Southampton, Great Britain. “Commercial products for swaddling should have a loose pouch or sack for the babies’ legs and feet, allowing [for] plenty of hip movement.”