I am a scientist specialized in mitochondria and genetics, but above all, I am just curious guy who loves learning new things.


Sleeping with your baby can be dangerous, but it can be protective if it is done right.

In 10 seconds? Co-sleeping has been considered a risk factor for Sudden Infant Death Syndrome (SIDS), but recent research shows that it is only a risk when combined with risky behaviors, like smoking, using alcohol or drugs, or sleeping in non-suitable locations, like sofas, and without those hazardous situations, co-sleeping may even be protective.

So why do we think it is a risk? For decades, pediatricians have found increased rates of asphyxiation and sudden death in infants who sleep in the same bed as their parents. But unfortunately, in our Western society co-sleeping is not always a choice but most of the time it is an obligation, families with tight budgets cannot afford a separate bed or room for their children. So, regularly, co-sleeping is not done in ideal conditions, on the contrary, it is often associated with the use of drugs, alcohol abuse, smoking, violence and overall bad sleeping (and living) conditions.

And without those hazardous situations, co-sleeping is no longer a risk? Several studies have shown that the biggest risks are due to co-sleeping on a sofa, sleeping with a parent who drank more than two units of alcohol and with someone who smokes, particularly for infants less than 3 months old. But in the absence of these hazards there is no risk associated with co-sleeping and it even seems protective for infants older than 3 months.

But how can bed-sharing be protective? In addition to facilitating breastfeeding and improving parent-child bonding, co-sleeping also promotes infant arousals during sleep, with more frequent, but shorter, awakenings per night than a solo-sleeper. This may be protective since it has been hypothesized that SIDS may be caused by arousal deficit: infants that sleep too heavily “forget” to breath and can suffer from apnea. Indeed, in an Australian and Danish study, staining for beta-amyloid precursor protein (beta-APP), a method to detect brain injury due to trauma or hypoxia, was significantly higher in infants who were sleeping alone than in co-sleepers.

Are there any other benefits? Co-sleeping has been found to help entrain the circadian rhythm in preterm infants, helping to create a good sleep cycle. Also, cortisol levels of coslept babies are lower, suggesting lower stress and higher blood glucose. And it can even make better fathers by lowering their testosterone levels, and studies have shown that lower testosterone is associated with fathers who are more involved in childcare .


Sleep patterns of co-sleeping and solitary sleeping infants and mothers: a longitudinal study.

Abstract: Controversies exist regarding the impact of co-sleeping on infant sleep quality. In this context, the current study examined: (a) the differences in objective and subjective sleep patterns between co-sleeping (mostly room-sharing) and solitary sleeping mother-infant dyads; (b) the predictive links between maternal sleep during pregnancy and postnatal sleeping arrangement; (c) the bi-directional prospective associations between sleeping arrangement and infant/maternal sleep quality at three and six months postpartum.The sample included 153 families recruited during pregnancy. Data were obtained in home settings during the third trimester of pregnancy and at three and six months postpartum. Mothers were asked to monitor their own sleep and their infants' sleep for five nights using actigraphy and sleep diaries. Questionnaires were used to assess sleeping arrangements, feeding methods, socio-demographic characteristics, and maternal depressive and anxiety symptoms.Mothers of co-sleeping infants reported more infant night-wakings than mothers of solitary sleeping infants. However, none of the objective sleep measures was significantly different between co-sleeping and solitary sleeping infants, after controlling for feeding techniques. Co-sleeping mothers had significantly more objective and subjective sleep disturbances than mothers in the solitary sleeping group. Moreover, poorer maternal sleep during pregnancy and at three months postpartum predicted higher levels of co-sleeping at six months.Mothers of co-sleeping infants report more infant night-wakings, and experience poorer sleep than mothers of solitary sleeping infants. The quality of maternal sleep should be taken into clinical consideration when parents consult about co-sleeping.

Pub.: 27 Oct '15, Pinned: 08 Sep '17

Alcohol as a risk factor for sudden infant death syndrome (SIDS).

Abstract: To test whether alcohol is a risk factor for sudden infant death syndrome (SIDS).US epidemiological study using computerized death certificates, linked birth and infant death dataset, and Fatality Analysis Reporting System.All SIDS cases (n = 129,090) and other infant deaths (n = 295,151) from 1973-2006; all persons involved in late-night alcohol-related crashes (n = 135,946) from 1994-2008.Three measures were used: the expected number of deaths on New Year versus the observed number (expected values were determined using a locally weighted scatterplot smoothing polynomial), the average number of weekend deaths versus the average number of weekday deaths, and the SIDS death rate for children of alcohol-consuming versus non-alcohol-consuming mothers.These measures indicate that the largest spikes in alcohol consumption and in SIDS (33%) occur on New Year, alcohol consumption and SIDS increase significantly on weekends, and children of alcohol-consuming mothers are much more likely to die from SIDS than are children of non-alcohol-consuming mothers.Alcohol consumption appears to be a risk factor for sudden infant death syndrome, although it is unclear whether alcohol is an independent risk factor, a risk factor only in conjunction with other known risk factors (like co-sleeping), or a proxy for other risk factors associated with occasions when alcohol consumption increases (like smoking). Our findings suggest that caretakers and authorities should be informed that alcohol impairs parental capacity and might be a risk factor for sudden infant death syndrome; in addition, future research should further explore possible connections between sudden infant death syndrome and alcohol.

Pub.: 10 Nov '10, Pinned: 08 Sep '17

Does β-APP staining of the brain in infant bed-sharing deaths differentiate these cases from sudden infant death syndrome?

Abstract: Archival cerebral tissue from infants whose deaths were attributed to sudden infant death syndrome (SIDS) from South Australia and Western Denmark were stained for β-amyloid precursor protein (β-APP) and graded according to a simple scoring chart. The resulting APP scores were correlated with sleeping situation (shared vs. alone) showing a significantly higher amount of β-APP staining in the non-bed-sharing, than in the bed-sharing infants (Mann-Whitney, Australia: p = 0.0128, Denmark: p = 0.0014, Combined: p = 0.0031). There was also a marked but non-significant difference in sex distribution between bed-sharers and non-bed-sharers with a male to female ratio of 1:1 in the first group and 2:1 in the latter. Of 48 Australian and 76 Danish SIDS infants, β-APP staining was present in 116 (94%) cases. The eight negative cases were all from the Danish cohort. This study has shown that the amount of β-APP staining was significantly higher in infants who were sleeping alone compared to those who were bed-sharing with one or more adults, in both an Australian and Danish cohort of SIDS infants. Whether this results from differences in the speed with which these infants die, differences in lethal mechanisms involving possible accidental asphyxiation in shared sleepers, or differences in the number of previous hypoxic-ischemic events, remains to be clarified.

Pub.: 08 Oct '14, Pinned: 08 Sep '17

The role of beta-amyloid precursor protein (beta-APP) staining in the neuropathologic evaluation of sudden infant death and in the initiation of clinical investigations of subsequent siblings.

Abstract: This report highlights the importance of undertaking immunohistochemical staining of the brains of infants who die unexpectedly, as it may not only assist with the evaluation of the cause of death in an individual infant but may also help with the clinical management of subsequent siblings. A 5-month-old male infant who died suddenly was found to have diffuse beta-amyloid precursor protein (beta-APP) staining in the brain, with no unusual features in his history, death scene examination, routine autopsy dissection, and ancillary tests to suggest any definite cause of death. Due to the beta-APP staining, the possibility of previous episodes of occult trauma, apparent life threatening events (ALTEs), and accidental or inflicted suffocation was raised in the autopsy report. As detailed analyses and investigations provided no supportive evidence for trauma or inflicted injury, hypoxia was clinically considered the most likely cause. Because of these concerns, sleeping oxygen saturation levels were monitored following the birth of a subsequent sibling who had normal APGAR scores and no evidence of any health problems. Oxygen desaturation to 70% occurred in association with a color change while on the postnatal ward, and a subsequent polysomnogram showed multiple episodic significant desaturations to around 80% in association with central apnea. Other testing was unremarkable. These cases demonstrate that beta-APP staining of the brain may not only provide clues as to possible mechanisms of death in pediatric forensic cases but may indicate a need for careful clinical evaluation of subsequent siblings for possible central apnea requiring oxygen therapy.

Pub.: 30 Nov '06, Pinned: 08 Sep '17

Bed-sharing in the absence of hazardous circumstances: is there a risk of sudden infant death syndrome? An analysis from two case-control studies conducted in the UK.

Abstract: The risk of sudden infant death syndrome (SIDS) among infants who co-sleep in the absence of hazardous circumstances is unclear and needs to be quantified.Combined individual-analysis of two population-based case-control studies of SIDS infants and controls comparable for age and time of last sleep.Parents of 400 SIDS infants and 1386 controls provided information from five English health regions between 1993-6 (population: 17.7 million) and one of these regions between 2003-6 (population:4.9 million).Over a third of SIDS infants (36%) were found co-sleeping with an adult at the time of death compared to 15% of control infants after the reference sleep (multivariate OR = 3.9 [95% CI: 2.7-5.6]). The multivariable risk associated with co-sleeping on a sofa (OR = 18.3 [95% CI: 7.1-47.4]) or next to a parent who drank more than two units of alcohol (OR = 18.3 [95% CI: 7.7-43.5]) was very high and significant for infants of all ages. The risk associated with co-sleeping next to someone who smoked was significant for infants under 3 months old (OR = 8.9 [95% CI: 5.3-15.1]) but not for older infants (OR = 1.4 [95% CI: 0.7-2.8]). The multivariable risk associated with bed-sharing in the absence of these hazards was not significant overall (OR = 1.1 [95% CI: 0.6-2.0]), for infants less than 3 months old (OR = 1.6 [95% CI: 0.96-2.7]), and was in the direction of protection for older infants (OR = 0.1 [95% CI: 0.01-0.5]). Dummy use was associated with a lower risk of SIDS only among co-sleepers and prone sleeping was a higher risk only among infants sleeping alone.These findings support a public health strategy that underlines specific hazardous co-sleeping environments parents should avoid. Sofa-sharing is not a safe alternative to bed-sharing and bed-sharing should be avoided if parents consume alcohol, smoke or take drugs or if the infant is pre-term.

Pub.: 23 Sep '14, Pinned: 08 Sep '17

Does cosleeping contribute to lower testosterone levels in fathers? Evidence from the Philippines.

Abstract: Because cross-species evidence suggests that high testosterone (T) may interfere with paternal investment, the relationships between men's transition to parenting and changes in their T are of growing interest. Studies of human males suggest that fathers who provide childcare often have lower T than uninvolved fathers, but no studies to date have evaluated how nighttime sleep proximity between fathers and their offspring may affect T. Using data collected in 2005 and 2009 from a sample of men (n = 362; age 26.0 ± 0.3 years in 2009) residing in metropolitan Cebu, Philippines, we evaluated fathers' T based on whether they slept on the same surface as their children (same surface cosleepers), slept on a different surface but in the same room (roomsharers), or slept separately from their children (solitary sleepers). A large majority (92%) of fathers in this sample reported practicing same surface cosleeping. Compared to fathers who slept solitarily, same surface cosleeping fathers had significantly lower evening (PM) T and also showed a greater diurnal decline in T from waking to evening (both p<0.05). Among men who were not fathers at baseline (2005), fathers who were cosleepers at follow-up (2009) experienced a significantly greater longitudinal decline in PM T over the 4.5-year study period (p<0.01) compared to solitary sleeping fathers. Among these same men, baseline T did not predict fathers' sleeping arrangements at follow-up (p>0.2). These results are consistent with previous findings indicating that daytime father-child interaction contributes to lower T among fathers. Our findings specifically suggest that close sleep proximity between fathers and their offspring results in greater longitudinal decreases in T as men transition to fatherhood and lower PM T overall compared to solitary sleeping fathers.

Pub.: 08 Sep '12, Pinned: 08 Sep '17

Observations on increased accidental asphyxia deaths in infancy while cosleeping in the state of Maryland.

Abstract: The Office of the Chief Medical Examiner (OCME) has recorded a significant increase of accidental asphyxia deaths in infancy associated with cosleeping in the state of Maryland in 2003. A total of 102 infants died suddenly and unexpectedly during 2003 in the state of Maryland. Of the 102 infants, 46 (45%) were found cosleeping. The frequency of cosleeping among these 102 infants was 28% (29/102) for black infants and 15% (15/102) for white infants. Ten of the 46 cosleeping infant deaths (20%) were determined to be the result of accidental asphyxia, and 28 cosleeping infant deaths (59%) were classified as "undetermined" because the possibility of asphyxia due to overlay while cosleeping could not be ruled out. Only 21 cases were determined to be Sudden Infant Death Syndrome (SIDS), which is consistent with the continuous decline of SIDS death in Maryland since 1994. The age of asphyxiated cosleeping infants ranged from 15 days to 9 months. Nine out of the 10 asphyxia deaths were black infants. The most common sleeping location of the asphyxia infants was on a couch/sofa, followed by an adult bed. Crib availability was documented in all of the cosleeping cases. A majority (61%) of the cosleeping infants (28/46) had an available crib or bassinet at home and 9 out of 10 asphyxiated cosleeping infants had a crib at home at the time of the incident. This report focuses on the detailed scene investigation findings of infant victims who died of asphyxia while cosleeping. The shift of diagnosis in sudden infant death investigation is also addressed.

Pub.: 11 Nov '09, Pinned: 08 Sep '17

Mother-infant cosleeping, breastfeeding and sudden infant death syndrome: what biological anthropology has discovered about normal infant sleep and pediatric sleep medicine.

Abstract: Twenty years ago a new area of inquiry was launched when anthropologists proposed that an evolutionary perspective on infancy could contribute to our understanding of unexplained infant deaths. Here we review two decades of research examining parent-infant sleep practices and the variability of maternal and infant sleep physiology and behavior in social and solitary sleeping environments. The results challenge clinical wisdom regarding "normal" infant sleep, and over the past two decades the perspective of evolutionary pediatrics has challenged the supremacy of pediatric sleep medicine in defining what are appropriate sleep environments and behaviors for healthy human infants. In this review, we employ a biocultural approach that integrates diverse lines of evidence in order to illustrate the limitations of pediatric sleep medicine in adopting a view of infants that prioritizes recent western social values over the human infant's biological heritage. We review what is known regarding infant sleeping arrangements among nonhuman primates and briefly explore the possible paleoecological context within which early human sleep patterns and parent-infant sleeping arrangements might have evolved. The first challenges made by anthropologists to the pediatric and SIDS research communities are traced, and two decades of studies into the behavior and physiology of mothers and infants sleeping together are presented up to the present. Laboratory, hospital and home studies are used to assess the biological functions of shared mother-infant sleep, especially with regard to breastfeeding promotion and SIDS reduction. Finally, we encourage other anthropologists to participate in pediatric sleep research using the unique skills and insights anthropological data provide. By employing comparative, evolutionary and cross-cultural perspectives an anthropological approach stimulates new research insights that influence the traditional medical paradigm and help to make it more inclusive. That this review will potentially stimulate similar research by other anthropologists is one obvious goal. That this article might do so makes it ever more possible that anthropologically inspired work on infant sleep will ultimately lead to infant sleep scientists, pediatricians, and parents becoming more informed about the consequences of caring for human infants in ways that are not congruent with their evolutionary biology.

Pub.: 30 Nov '07, Pinned: 08 Sep '17