Sleeping with the baby

Bed sharing, breastfeeding and sudden infant death Blair PS, Heron J, Fleming PJ. Relationship between bed sharing and breastfeeding: longitudinal, population-based analysis. Pediatrics 2010;126: e1119-e1126 This study used prospective, population-based data from the Avon Longitudinal Study of Parents and Children in the United Kingdom to investigate nocturnal bed sharing at 0-2, 6-8, 17-20, 30-33 and 42-45 months of age, and its relationship with breastfeeding. Of 14’062 live births recorded between April 1991 and December 1992, 7’447 (53%) had data available for all time points. Latent class analysis, a multivariate statistical method that identifies unobservable subgroups within a population, identified four mutually exclusive groups: non sharers (66%), early bed sharers (only in infancy) (13%), late bed sharers (after the first year) (15%), and constant bed sharers (throughout the 4 years) (6%). Higher maternal education and social class were positively associated with early bed-sharing, negatively associated with late bedsharing, and not associated with constant bedsharing. Late bed sharers had a 72% higher probability of breastfeeding at 12 months, early bed-sharers breastfed almost 2.5 higher more, and constant bed-sharers 5.3 times more, compared to non bed-sharers. The prevalence of breastfeeding was significantly higher among the groups that shared beds constantly or early for each of the first 15 months after birth. The authors conclude that advice on whether bedsharing should be discouraged needs to take into account the important relationship with breastfeeding. Trachtenberg FL, Haas EA, Kinney HC, Stanley C, Krous HF. Risk factor changes for Sudden Infant Death Syndrome after initiation of Back-to-Sleep campaign. Pediatrics 2012;129;630-8 This study used the records of 568 SIDS deaths occurred in San Diego, USA, from 1991 to 2008 to test the hypothesis that age, prevalence and pattern of risk factors changed after initiation of the Back-to-Sleep (BTS) campaign in 1994. Risks were divided into intrinsic (e.g., male gender, prematurity, prenatal exposure to cigarette smoke or alcohol) and extrinsic (e.g., prone sleeping, bed sharing, over-bundling, soft bedding). Between 1991-1993 and 1996-2008, the percentage of SIDS infants found prone decreased from 84% to 49%, bed-sharing increased from 19% to 38%, especially among infants less than 2 months (29% vs. 64%), prematurity increased from 20% to 29%, whereas symptoms of upper respiratory tract infection decreased from 47% to 25%. Ninety-nine percent of SIDS infants had at least one risk factor, 57% had at least two extrinsic and one intrinsic risk factor, and only 5% had no extrinsic risk. The average number of risks per SIDS infant did not change after initiation of the BTS campaign. SIDS infants in the BTS era show more variation in risk factors. There was a consistently high prevalence of both intrinsic and especially extrinsic risks both before and during the BTS campaign. Risk reduction campaigns emphasizing the importance of avoiding multiple and simultaneous SIDS risks are essential to prevent SIDS, including among infants who may already be vulnerable. Ball HL, Moya E, Fairley L, Westman J, Oddie S, Wright J. Infant care practices related to sudden infant death syndrome in South Asian and White British families in the UK. Pediatr Perinat Epidemiol 2012;26:3-12 In the UK, infants of South Asian parents have a lower rate of SIDS than white British infants. Infant care and life style behaviours are strongly associated with SIDS risk. This paper describes and explores variability in infant care between white British and South Asian families (of Bangladeshi, Indian or Pakistani the vast majority origin) in Bradford, and identifies areas for targeted SIDS intervention. A cross-sectional telephone interview study was conducted involving 2’560 families with 2to 4-month-old singleton infants. Outcome measures were prevalence of self-reported practices in infant sleeping environment, sharing sleep surfaces, breastfeeding, use of pacifier and life-style behaviours. It was found that, compared with white British infants, Pakistani infants were more likely to sleep in an adult bed 8.5 times, to be positioned on their side for sleep 4.4 times, to have a pillow in their sleep environment almost 10 times, to sleep under a duvet 3.2 times, to be swaddled for sleep 1.5 times, to ever bed-share 2 times, to regularly bed-share 3.5 times, to have been ever breastfed 2 times, and to have been breastfed for 8 weeks or more 1.6 times. In addition, Pakistani infants were 95% less likely to sleep in a room alone, 65% to use feet-to-foot position, 48% to sleep with a soft toy, 80% to use an infant sleeping bag, 78% to ever sofashare, 78% to be receiving solid foods, and 60% to use a pacifier at night. Pakistani infants were also 93% less likely to be exposed to maternal smoking and to alcohol consumption by either parent. No difference was found in the prevalence of prone sleeping. Night-time infant care, therefore, differed significantly between South Asian and White British families. South Asian infant care practices were more likely to protect infants from the most important SIDS risks such as smoking, alcohol consumption, sofa-sharing and solitary sleep. These differences may explain the lower rate of SIDS in this population. Ball HL, Moya E, Fairley L, Westman J, Oddie S, Wright J. Bedand sofa-sharing practices in a UK biethnic population. Pediatrics 2012;129:e673-e681 In the United Kingdom, as in the United States and New Zealand, bed-sharing is a cultural practice among particular ethnic minority groups. The authors carried out a cohort study in UK Pakistani and white British population aiming to describe cultural differences in bed and sofa-sharing, associated with breastfeeding practices. 3082 mothers with single births were interviewed when their babies were aged 2 to 4 months, showing that 15.5% of families had ever bed-shared; 7.2% of families regularly bed-shared and 9.4% had ever sofa-shared, while 1.4% reported both. Potential risk factors were controlled and statistical analysis was performed. The results showed an association between (especially regular) bed-sharing and breastfeeding, suggesting that bed-sharing is more common among white British than Pakistani mothers who breastfeed more than 8 weeks. The authors conclude that caution is needed in making recommendations regarding avoidance of bed-sharing, which does not appear to carry the same risk for all families, and can lead to adoption of more risky strategies, such as sofa-sharing, and to reduce breastfeeding. Gettler LT, McKenna JJ. Evolutionary perspectives on mother-infant sleep proximity and breastfeeding in a laboratory setting. American Journal of Physical Anthropology 2011;144:454-62 The authors of this well-defined and processed study observed and filmed 36 mother-infant pairs over a 3night period in a laboratory-setting in California. Participants in the “bed-sharing dyads” group (n=20) slept, mother and child, on the same surface (as they did routinely at home), while participants in the group of “solitary sleeping dyads” (n=16) slept in separate rooms (also as at home). All infants were breastfed on demand. Mothers and infants were selected following a thorough process based on numerous criteria for both mothers (Latina, under 38 years, no alcohol, cigarette or drug use history, prenatal care...) and infants (7-18 weeks of age, good health, normal development, normal gestational age, AGPAR score 8 or above...). During the first night, as hypothesized by the authors, participants in the bedsharing group fed more often and at shorter intervals between feeds than those in the solitary sleeping group (respectively 4.5 and 2.6 times per night at intervals of 116.2 and of 161.9 minutes). There were no notable differences between male and female infants. A particular novelty of the study was that participants were filmed, thus allowing for more objectivity. The video-taping showed how physical proximity enhanced awakening and facilitated breastfeeding episodes. The discussion led by the authors in the article is of particular interest as they explain the anthropological context of bed-sharing: all mammal mothers sleep with their offspring; the human being is less developed at birth than other mammals and requires constant protection, proximity and feeding; at birth the infant’s brain is only 25% that of the adult’s and develops through regular feeding; human babies acquire more than 50% of their nutritional needs during night feeds; human milk is low in fat and proteins which explains the need to feed often. They also introduce a historical and cultural perspective: systematic efforts to separate mothers from infants at night-time are recent and mostly a Western world phenomenon; more than 65% of breast-feeding mothers in the UK bed-share for some time during the baby’s first weeks of life despite efforts to constrain this. The authors’ conclusions are important for breastfeeding advocates: 1) research on breastfeeding initiation and duration should include data on sleep practices as mother-infant proximity including during the night – does seem to directly influence breastfeeding length and exclusive breastfeeding; 2) solitary sleep, a culturally-guided phenomenon, is not neutral and influences infant health and development; 3) in contexts where mothers and infants are separated during long daytime periods (working mothers for example) it may be particularly important that infants sleep in close proximity to their mothers in order to easily breastfeed on demand and thus obtain the necessary nutritional, energetic and immunological benefits of their mother’s milk. Baddock SA, Galland BC, Bolton DPG, Williams SM, Taylor BJ. Hypoxic and hypercapnic events in young infants during bed-sharing. Pediatrics 2012; 130;237-44 The objective of this study was to identify de-saturation events (arterial oxygen saturation [SaO2] less than 90%) and rebreathing events (inspired carbon dioxide (CO2) more than 3%), in bed-sharing (BS) versus cot-sleeping (CS) infants. Forty healthy, term infants, aged 0 to 6 months who regularly bed-shared with at least one parent more than 5 hours per night and 40 age-matched CS infants were recruited in Dunedin, New Zealand. Overnight parent and infant behaviour (via infrared video), SaO2, inspired CO2 around the infant’s face, and body temperature were recorded during sleep at home over two consecutive nights. De-saturation events were twice as common in BS infants, associated partly with the warmer micro-environment during BS. More than 70% of de-saturations in both groups were preceded by central apnoea of 5 to 10 seconds with no accompanying bradycardia, usually in active sleep. Apnoea lasting more than 15 seconds was rare (BS infants: three events; CS infants: 6 events), as was desaturation to less than 80% SaO2 (BS infants: three events; CS infants: four events). Eighty episodes of rebreathing were identified from 22 BS infants and 1 CS infant, almost all preceded by head covering. During rebreathing, SaO2 was maintained at the baseline of 97.6%. All BS and CS infants were at low risk of SIDS and maintained normal oxygenation. More research is needed on the effect of repeated exposure to oxygen desaturation in vulnerable infants and on the ability of these infants to respond effectively to rebreathing caused by head covering. Morgan BE, Horn AR, Bergman NJ. Should neonates sleep alone? Biol Psychiatry 2011;70:817-25 This study was carried out to investigate the impact of maternal-neonate separation (MNS) on heart rate variability (HRV), a measure of involuntary nervous system activity in response to stress. The authors measured HRV in 16 2-day-old full-term neonates sleeping in skin-to-skin contact (SSC) with their mothers and sleeping alone, for 1 hour in each place, before discharge from hospital at the University of Cape Town, South Africa. They recorded cardiac interbeat intervals and continuous electrocardiogram using two independent devices. In addition, they continuously observed and recorded infant behaviour using a validated scale. The results showed a 176% increase in involuntary nervous system activity and an 86% decrease in quiet sleep duration during MNS compared with SSC. MNS in mammals is a model for studying the effects of stress on the development and function of physiological systems. In contrast, for humans, MNS is a Western norm and often a standard medical practice, the physiological impact of which is unknown. This study shows that MNS is associated with a dramatic increase in HRV, possibly indicative of anxious involuntary arousal. MNS had also a profoundly negative impact on quiet sleep duration. MNS may be a stressor the human neonate is not well-evolved to cope with, and may not be benign. Tollenaar MS, Beijers R, Jansen J, Riksen-Walraven JMA, de Weerth C. Solitary sleeping in young infants is associated with heightened cortisol reactivity to a bathing session but not to a vaccination. Psycho-neuroendocrinology 2012;37: 167-77 The authors of this research followed 163 mother-infant pairs in the Netherlands to assess if different sleeping arrangements modified the level of stress in infants less than 2 months-old in two different stressful situations: bathing at the age of 5 weeks, and vaccination at the age of 8 weeks. Stress levels were measured by the level of cortisol in the infants’ saliva: the more cortisol, the higher the stress. Measurements were made three times in each case, before, 25 minutes after and 40 minutes after bathing and vaccination. The three sleeping modes considered were: co-sleeping (more than 90% of the time, either bed-sharing and/or room-sharing with parents); solitary sleeping (more than 90% of the time); and partial co-sleeping (11-90% of the time). Important confounders were taken into account: quality of maternal care-giving behaviour; breastfeeding; number of infant night awakenings and total sleep duration. A number of other child and maternal variables were also considered, such as gender, birth weight, maternal age, smoking, etc. Mothers were requested to fill a diary explaining sleeping habits, feeding activities, etc., and the two stressful situations were videotaped. Concerning the bathing session, the solitary sleep group showed a higher cortisol reaction than the other two groups, including 40 minutes after the bath; breastfeeding did not have a significant impact over time. In the vaccination situation, in comparison to the solitary sleepers, all co-sleepers demonstrated higher levels of cortisol before and well after the situation had ended; in comparison to bottle-fed infants, breastfed infants, however, showed higher levels of cortisol before vaccination, but lower levels 40 minutes after. Other indirect results included: co-sleepers were breastfed more often than solitary sleepers and though they woke more often, the total nightly amount of sleep equalled that of the other infants. Also, authors reflected that, in order to lower infants’ stress levels, it may suffice that they sleep in proximity with their parents, rather than with them. Prepared by the Geneva Infant Feeding Association (GIFA), an affiliate of the International Baby Food Action Network (IBFAN). Guest editor: Helen Ball. Editorial team: Adriano Cattaneo, Lida Lhotska, Robert Peck, Elaine Petitat-Côté and Marina Rea. Lena Nyffenegger laid out the issue. 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