Many of us think of swaddling as a useful way to calm and comfort small babies. For years, when I made home visits to new families as a lactation consultant in private practice, I used to teach mothers and other family members techniques for swaddling newborns as a way to keep their hands contained when they put them to the breast. However, recently, I received an email from a parent educator whose friend had heard me speak at a recent breastfeeding conference. Her friend quoted me as saying that “swaddling is bad,” and as a Happiest Baby instructor, the educator was concerned. She said she believed that swaddling must be okay since it was “something other cultures have used for a long time.” She asked me to share with her the studies I cited in my talk. I responded by clarifying that I had not actually said “swaddling is bad,” but that in recent years, my opinion on swaddling has changed.
In my book, Breastfeeding Answers Made Simple: A Guide for Helping Mothers (2010), I note that, although swaddled babies appear calmer and sleep more, research has found that regular swaddling can contribute to negative breastfeeding outcomes. Routinely swaddling babies during the first few days of life is associated with a delay in the first breastfeeding, less effective suckling at the breast, decreased intake of mother’s milk and greater infant weight loss. Routine swaddling during the first few months of life is associated with a variety of other negative health outcomes. I emailed the educator some of the studies I described during my talk so that she could read them and come to her own conclusions. When I read the studies cited at the end of this article for the first time, the question I asked myself was, “Are swaddled babies really happier, or does swaddling cause newborns to shut down?” There is no doubt that a calmer baby makes new parents’ lives easier and more pleasant, but I wondered from the baby’s perspective whether swaddling is a positive or a negative.
As the parent educator who wrote to me noted, swaddling—also known as bundling—has been practiced historically in many parts of the world. Research has found that swaddled babies arouse less and sleep longer (Franco et al., 2005). That may sound good, but in the early hours and days after birth this can lead to less breastfeeding, which has definite drawbacks (see below). Although many studies have examined the effects of swaddling, in one review of the research, every randomized control trial compared swaddling with practices involving separation from mother, such as keeping babies in incubators or giving them a pacifier or massage (van Sleuwen, Engelberts et al. 2007). None of the studies compared swaddling with being held or carried by the mother.
In a U.S. study of 21 babies after a vaginal birth, researchers compared two groups (Moore & Anderson, 2007). Immediately after birth, one group was laid tummy down, skin-to-skin on the mother’s body, removed for a short examination, and then returned to the mother’s body where these babies remained in skin-to-skin contact for two hours. The other group was shown briefly to the mother after birth, examined, and swaddled with hands free and returned to the mother. The group that was swaddled during their first two hours showed delayed feeding behaviors, suckled less competently at their first breastfeeding, and established effective breastfeeding later.
When swaddling is added to other newborn stressors, there are more negative repercussions. One study of 176 mothers and babies done in Russia with a team of Swedish, Russian, and Canadian researchers was designed to measure the effects of postpartum practices and resulted in several published papers (Bystrova, Matthiesen, Vorontsov et al., 2007; Bystrova, Matthiesen, Widstrom et al., 2007; Bystrova, Widstrom et al., 2007; Bystrova et al., 2003). These researchers compared outcomes in four groups of newborns, who were 1. kept in skin-to-skin contact with mother for 30 to 120 minutes after birth; 2. held in mother’s arms wearing clothes; 3. separated from mother at birth and returned to her after two hours; 4. taken to the hospital nursery at birth and returned to mother for breastfeeding seven times each day at regular intervals. In each group, some babies were swaddled and some wore clothes. The researchers reported that skin-to-skin contact reduced “the stress of being born” and found the babies kept skinto-skin after birth had the highest body temperatures (Bystrova et al., 2003). Swaddled babies separated during their first two hours lost more weight. Among the babies taken to the nursery for the first two hours after birth and then returned to their mothers for the rest of the hospital stay (group 3 above), the swaddled babies had a significantly greater weight loss on their third and fifth days (Bystrova, Matthiesen, Widstrom et al., 2007). This significant difference in weight indicates that the first two hours after birth may be a “critical period” during which mother-baby separation can undermine infant stability and growth. Swaddled babies kept in the nursery were colder and consumed less milk. Among the babies in the “nursery group” (group 4 above), some were swaddled and some were not. Those babies in the nursery group who were swaddled had the lowest foot temperature of any of the babies in any of the study groups.
Overall, the babies in the nursery group consumed 37% less mother’s milk on their fourth day compared with the babies kept with their mothers. Newborns who were both separated and swaddled consumed less mother’s milk overall than those who were not swaddled. Their mothers also produced less milk on the fourth day and they had a shorter duration of breastfeeding overall (Bystrova, Matthiesen, Widstrom et al., 2007). Swaddled babies in the nursery lost more weight despite consuming more formula. In addition to separation, supplementing with formula (another physiological stressor) was found to produce greater weight loss among the swaddled newborns. The only study babies to receive formula were some of those in the nursery group. The supplemented and unsupplemented babies in the nursery group consumed similar amounts of milk daily, but the supplemented newborns who were also swaddled lost significantly more weight on their third and fifth days as compared with the newborns who were either not swaddled or not supplemented (Bystrova, Matthiesen, Widstrom et al., 2007). The researchers suggested possible reasons for this greater weight loss among the swaddled, separated, and supplemented babies:
Common sense tells us that wrapping a baby in a blanket should help keep him warm. However, research has found mother-baby skin-to-skin contact to be far more effective at maintaining a newborn’s body temperature. If the room is cool or there are other reasons to be concerned about the baby’s temperature, a much better strategy than either swaddling or putting baby in an infant warmer is to keep baby on mother’s body, putting blankets (either warmed or unwarmed) over both mother and baby (Galligan, 2006; Ludington-Hoe, Ferreira, Swinth, & Ceccardi, 2003; WHO, 2003). If the mother is not willing or available, skin-to-skin contact with the father is an excellent second choice. Mother-baby body contact is also important for other reasons. In addition to keeping baby warm, it also releases baby’s inborn feeding reflexes (Colson, Meek, & Hawdon, 2008), which leads to more breastfeeding. This has been fo nd even among ate preterm babies (Colson, DeRooy, & Hawdon, 2003). Postpartum practices associated with more early breastfeeding should be encouraged, as more feedings in the first 24 hours of life have been associated with lower rates of exaggerated newborn jaundice on baby’s sixth day and less weight loss and greater milk intakes on the third and fifth days (Yamauchi & Yamanouchi, 1990).
But what about swaddling after hospital discharge? Once a baby is breastfeeding well, is there any reason to avoid swaddling? Many who advise new parents promote swaddling as a way to soothe fussy babies. While swaddling may be helpful when used occasionally, research from around the world has found negative health outcomes associated with routine swaddling during the first months.
One study of 186 babies in Turkey and China found that babies who were routinely swaddled during their first three months were four times more likely to develop pneumonia and other respiratory infections compared with babies who were not swaddled (Yurdakok, Yavuz, & Taylor, 1990).
When babies are swaddled tightly and their legs cannot bend and flex, this creates a greater risk of hip dysplasia, sometimes called “developmental dysplasia” (Sahin, Akturk et al. 2004; van Sleuwen, Engelberts et al. 2007).
One Australian case-control study that compared 22 babies who died of sudden infant death syndrome (SIDS) to 213 babies who did not found that swaddled babies laid face down (prone) to sleep were at 12 times greater risk for SIDS than babies laid face up (supine), compared to a three times greater risk in babies laid face down who were not swaddled (Ponsonby, Dwyer, Gibbons, Cochrane, & Wang, 1993).
If also in warm surroundings, swaddled babies are at risk of overheating, which in rare cases has been fatal (van Gestel, L’Hoir, ten Berge, Jansen, & Plotz, 2002).
After looking into the research, my own opinion of swaddling has changed. Rather than assuming babies should be swaddled after birth to keep them warm, I understand that in most cases a mother’s body is her newborn’s best “baby warmer.” My opinion of swaddling during breastfeeding has also changed. Rather than recommending mothers turn their babies into “baby burritos” to prevent waving arms from making latch more difficult, now I understand the role of “arm cycling” and other inborn feeding reflexes in helping babies get to the breast and feed (Colson et al., 2008). Instead, I suggest mothers simply lean back into semi-reclined, “laid-back” feeding positions. With baby tummy down on mother’s body, gravity makes these same inborn reflexes work for rather than against breastfeeding.
Although swaddling may sometimes be helpful, in light of this research, it may be best to limit its use and suggest parents consider alternatives during fussy times, such as skin-to-skin contact and baby carriers.
Nancy Mohrbacher, IBCLC, FILCA, is author of the new book Breastfeeding Answers Made Simple: A Guide for Helping Mothers (2010). She is also co-author (with Kathleen KendallTackett) of the popular book for parents, Breastfeeding Made Simple: Seven Natural Laws for Nursing Mothers, second edition, December 2010. She is co-author (with Julie Stock) of all three editions (1991, 1996, 2003) of The Breastfeeding Answer Book, a research-based counseling guide for lactation professionals, which has sold more than 130,000 copies worldwide, and author of The Breastfeeding Answer Book Pocket Guide Edition (2005).
Nancy has written for many publications and spoken at breastfeeding conferences around the world. Nancy began helping breastfeeding families as a volunteer in 1982, becoming board-certified in 1991. From 1993 to 2003 she founded and maintained a large private lactation practice in the Chicago area, where she worked with thousands of breastfeeding families. She still lives in Chicago, where she works as Lactation Consultant for Ameda Breastfeeding Products. In 2008 the International Lactation Consultant Association (ILCA) officially recognized Nancy’s contributions to the field of breastfeeding by awarding her the designation FILCA, Fellow of the International Lactation Consultant Association. Nancy was one of the first of 16 to be recognized for their lifetime achievements in breastfeeding.