Breastfeeding & Bedsharing: Still Useful (And Important) After All These Years - Page 2

Author // James J. McKenna, PhD

Article Index
Breastfeeding & Bedsharing: Still Useful (And Important) After All These Years
Page 2
Page 3
All Pages

Solitary Infant Sleep: A Historical Novelty

Emotions, designed by natural selection and controlled by the limbic system of the brain, motivate infants and children to protest sleep isolation from parents by crying. These emotions undoubtedly evolved to ameliorate what was throughout our evolution a life-threatening situation: separation from the caregiver.29

In recent decades, Western childcare strategies have favored early infant autonomy. Health professionals teach that parents should condition infants to sleep alone throughout the night with minimal parental intervention, including breastfeedings (according to some advice givers, the fewer number of breastfeeds the better).30,31 Parents are encouraged by some health professionals to train their infants to soothe themselves back to sleep. Pediatric sleep advisers say that infants should never be permitted to fall asleep at the breast or in the mother’s arms, even though this is the very context within which the infant’s natural falling asleep evolved. As many parents will attest, this advice proves highly problematic.

The exaggerated fear of suffocating an infant while co-sleeping may stem, in part, from Western cultural history. During the last 500 years, many economically destitute women in Paris, Brussels, Munich, and London (to name but a few locales) confessed to Catholic priests of having murdered their infants by overlying, in order to control family size. The priests threatened excommunication, fines, or imprisonment—and banned infants from parental beds.32,33

The legacy of this particular historical condition in the Western world probably converged with other changing social mores and customs (the emphasis on privacy, self-reliance, and individualism), providing a philosophical foundation for contemporary cultural beliefs and making it easier to find dangers associated with co-sleeping than to find (or assume) hidden benefits. The proliferation throughout Europe of the idea of romantic love, coupled with the belief in the importance of the husband– wife relationship, also may have promoted separate sleeping quarters. This physical separation, especially of the father from his children, also was seen as maximizing the father’s ability to dispense religious training and to display moral authority.

Co-sleeping and Solitary Sleeping Arrangements: Effects on Children

As I have noted elsewhere, the first published studies of people who coslept as infants contradict conventional Western assumptions that co-sleeping leads to negative psychological, emotional, and social outcomes later in life.34,35,36 A recent cross-sectional study of middle-class English children shows that children who never slept in their parents’ beds were more likely to be rated by teachers and parents as “harder to control” and “less happy” and exhibited a greater number of tantrums. Children never permitted to bed-share were also more fearful than those who slept in their parents’ beds.37

Other findings point to further advantages of co-sleeping over solitary sleeping. A survey of college-aged individuals found that men who had coslept with their parents between birth and five years of age had significantly higher self-esteem, experienced less guilt and anxiety, and reported greater frequency of sex. Men who had coslept between 6 and 11 years of age also had higher self-esteem. For women, co-sleeping during childhood was associated with less discomfort about physical contact and affection as adults.38 Another study found that women who had co-slept as children had higher self-esteem than those who did not.39 Indeed, co-sleeping appears to promote confidence, self-esteem, and intimacy, possibly by reflecting an attitude of parental acceptance.

A study of 86 children on military bases revealed that co-sleeping children received higher evaluations of their comportment from teachers than solitary-sleeping children and that they were underrepresented in psychiatriccare populations compared with children who did not co-sleep. The authors stated: Contrary to expectations, those children who had not had previous professional attention for emotional or behavioral problems co-slept more frequently than did children who were known to have had psychiatric intervention and lower parental ratings of adaptive functioning. The same finding occurred in a sample of boys one might consider Oedipal visitors (e.g., three-year-old and older boys who sleep with their mothers in the absence of the father)—a finding which directly opposes traditional psychoanalytic thought.40

The largest and possibly most systematic study to date, involving more than 1,400 subjects from five ethnic groups in Chicago and New York, found far more positive than negative adult outcomes for individuals who co-slept as children. The results were the same for almost all the ethnic groups (African Americans and Puerto Ricans in New York; Puerto Ricans, Dominicans, and Mexicans in Chicago). An especially robust finding, one that cut across all ethnic groups, was that co-sleepers exhibited a greater feeling of satisfaction with life.41

Physiological Studies of Mother–Infant Pairs

A study at the University of California- Irvine School of Medicine quantified differences in the sleep behavior and physiology of 70 Latina mothers and infants. More than 200 eight-hour polysonographic recordings were made of mothers and their infants sharing a bed or sleeping apart in adjacent rooms over three successive nights. We specifically compared how the solitary sleep environment and the bed-sharing environment affected two kinds of mother–infant pairs: pairs who routinely bed shared at home and pairs who routinely slept apart.

In randomly assigned order, each mother–infant pair spent two nights sleeping in their routine (home) sleeping condition and one night sleeping in the non-routine condition; that is, routine bed-sharing pairs slept in different rooms, routine solitary sleepers bed shared. All mothers and infants were healthy and nearly exclusively breastfeeding. The infants ranged in ages from 11 to 15 weeks (the peak age for SIDS).

We found that bed-sharing doubled the number of nightly breastfeeds and tripled the total nightly duration of breastfeeding. Bed-sharing also correlated with shorter average intervals between breastfeeding sessions. Among 70 nearly exclusively breastfeeding mothers, we found that the average interval between breastfeeds was approximately an hour and a half on the bed-sharing night—the approximate length of the mothers’ (adult) sleep cycle. That is, infant nighttime nutritional needs and feeding cycle while co-sleeping correlated with the general length of the ultradian (subcycle of sleep) sleep cycle (90–120 minutes) of the human adult—a correlation never before observed or proposed. When sleeping in separate bedrooms (but still within earshot), the breastfeeding interval was at least twice as long.42

The supine position is the universal sleep position for infants, having evolved specifically to facilitate and make possible nighttime breastfeeding. Indeed, our studies reveal that without instruction, breastfeeding mothers who routinely bed-share practically always placed their infants in the safe, supine position, probably because it is difficult, if not impossible, to breastfeed a prone, sleeping infant. From our infrared video studies of bed sharing mothers and infants, it appears that supine infant sleep maximizes the infant’s overall ability to control its microenvironment, and especially to elicit breastfeeds.43,44 In addition to permitting the infant to move toward and away from the breast, back-sleeping permits infants to remove blankets covering their faces, turn to face toward or away from the mother, touch their faces, wipe their noses, and, without a great deal of effort, suck on their fists or fingers, thus making loud sounds that will awaken their mothers, who often then offer breastfeeding.

Our studies also suggest that supine infant sleep in the breastfeeding/bed sharing context maximizes the chances of the baby detecting and responding in synchrony with the mother’s movements, sounds, and touches, and vice versa.45,46,47 The supine position of the infant promotes easy and constant communication between infant and mother, thus furthering mutual attachment and trust (a prerequisite for healthy infant development); in addition, it may stimulate the infant, through olfactory cues, to want to breastfeed more frequently, therein further suppressing the mother’s ovulation. This model constitutes yet another reason to view the mother– infant relationship not simply in terms of how mothers regulate their infants, but rather how mothers and infants mutually regulate each other’s physiology, including the mother’s reproductive status.

The increased breastfeeding that accompanies bed-sharing raises the possibility of enhanced immunological protection for the infant from potentially dangerous bacteria and viruses. Because bed-sharing in the context of a breastfeeding mother leads to the use of the single most important defense against sudden infant death syndrome (SIDS), the supine infant sleep position, we argued that the combination of breastfeeding and bed-sharing may provide and enhance potentially significant health gains for the baby and nonsmoking mother alike, including reducing the infant’s chances of dying from SIDS. Indeed, from the back-to-sleep campaign in 1992, which no doubt largely accounts for the significant reduction of SIDS, to the present, breastfeeding rates have increased to historic highs. If, as studies indicate, breastfeeding promotes the choice to bed-share, and more American parents are bed sharing than ever before, then perhaps these practices have also contributed to the reduction of SIDS since 1992. Most American breastfeeding mothers do not smoke and have access to safety information. Hence, the American situation of high rates of breastfeeding, high rates of supine infant sleep, reduced maternal smoking among this group, and safe bed-sharing could well parallel the situation in Japan, discussed above.

Infant–Parent Sleep Difficulties

Because infant sleep biology changes much more slowly than cultural values, sleep environments that are optimal for infants may not be the ones encouraged by the culture. Moreover, widely accepted infant sleep management strategies may be sufficient for some infants and children but unsuitable for others. Some families may apply norms established for bottle-fed, solitary-sleeping infants to their own children when it is inappropriate to do so, leading parents to conclude either that their parenting skills are deficient or that their child is uncooperative.

Ironically, this situation best describes what occurs in developed countries such as the United States, Great Britain, and Australia, where as many as one out of every three otherwise healthy children may have problems falling or staying asleep, after having first been conditioned to sleep alone.48 Rather than infant or caregiver deficiencies, such high percentages probably reflect overconfidence in the validity of our definitions and expectations about how infants should sleep, and the rigidity with which parents interpret and apply messages offered by health professionals.

Indeed, parents’ rigid expectations concerning how their infants should sleep can be used to predict the likelihood that infant/child sleep problems will manifest: The more rigid the expectations, the more likely it is that parents will report dissatisfaction with their child’s sleep behavior.49 Night awakenings constitute a problem only for parents who expect their children to sleep through the night.

It is only in the last century or so, and in a relatively small number of cultures, that parents and health professionals have become concerned with how infants should be conditioned to sleep. And, only in Western cultures are infants thought to need to learn to sleep, in this case alone and without parental contact. Most cultures simply take infant sleep for granted.