Skin‐to‐skin contact (SSC) between mothers and their infants has beneficial effects in both preterm and full‐term infants. Underlying mechanisms are largely unknown. This randomized controlled trial assessed whether daily SSC in full‐term mother–infant dyads: (1) decreases infants’ cortisol and behavioral reactivity to a mild naturalistic stressor, and (2) facilitates interaction quality between infants and mothers (i.e., improved maternal caregiving behavior and mother–infant adrenocortical synchrony). Pregnant Dutch women (N = 116) were recruited and randomly allocated to an SSC or care‐as‐usual condition. The SSC condition performed 1 h of SSC daily, from birth until postnatal week 5. In week 5, mothers bathed the infant (known mild stressor). Infant and maternal cortisol was sampled at baseline, 25 and 40 min after bathing, and infant and maternal behavior was rated. Results did not indicate effects of SSC on infant behavioral and cortisol reactivity to the bathing session. Similarly, no effect of SSC was found on maternal caregiving behavior and mother–infant adrenocortical synchrony. In conclusion, the findings provide no evidence that daily mother–infant SSC is associated with full‐term infants’ behavioral and adrenocortical stress reactivity or mother–infant interaction quality. Future studies should replicate these findings and unveil other potential mechanisms underlying beneficial effects of SSC.

Background: Daily skin‐to‐skin contact (SSC) during early infancy fosters the long‐term development of children born preterm. This is the first randomized controlled trial assessing the potential beneficial effects of daily SSC on executive functioning and socio‐emotional behavior of children born full‐term. Whether children of mothers who experienced prenatal stress and anxiety benefitted more from SSC was also explored. Methods: Pregnant women ( N = 116) were randomly assigned to a SSC or care‐as‐usual (CAU) condition. Women in the SSC condition were instructed to perform one hour of SSC daily from birth until postnatal week five. Prenatal stress was measured with questionnaires on general and pregnancy‐specific stress and anxiety completed by the mothers in gestational week 37. At child age three, mothers filled in questionnaires on children's executive functioning, and externalizing and internalizing behavior. Analyses were performed in an intention‐to‐treat (ITT), per‐protocol, and dose–response approach. Netherlands Trial Register: NL5591 . Results: In the ITT approach, fewer internalizing (95% CI = 0.11–1.00, U = 2148.50, r = .24, p = .001) and externalizing (95% CI = 0.04–2.62, t = 2.04, d = 0.38, p = .04) problems were reported in the SSC condition compared to the CAU condition. Multivariate analyses of variance did not show group differences on executive functioning. Additional analyses of covariance showed no moderations by maternal prenatal stress. Conclusions: Current findings indicate that early daily SSC in full‐term infants may foster children's behavioral development. Future replications, including behavioral observations of child behavior to complement maternal reports, are warranted.

Background. Although spending time outdoors is beneficial for development, little is known about outdoor time during infancy. The aim of this study was to assess frequencies and durations of (1a) outdoor walking and carrying in mother–infant dyads and (1b) infant outdoor sleeping in a stationary cot or pram. We furthermore aimed to identify associations of (2a) outdoor walking and carrying and (2b) infant outdoor sleeping, with infant, maternal and environmental sample characteristics. Methods. An online survey was distributed among mothers of 0- to 12-month-old infants. Initially, 1453 mothers were recruited, of which 1275 were included in the analyses. With respect to (1a) the outcomes of interest were: mother–infant dyads’ total weekly duration of walking in minutes, frequency of walking on weekdays, as well as weekends, and the frequency of using an infant carrier during walks, as well as the daily duration of carrying in hours (indoors and outdoors together). With respect to (1b) the outcome variables were: placing the infant outdoors to sleep (yes/no), the total weekly duration of outdoor sleeping and the weekly frequency of outdoor sleeping. For aim 2, associations of the outcome variables with infant (i.e., age), maternal (i.e., working status) and environmental (i.e., house type) sample characteristics were assessed. Results. Mother–infant dyads engaged in walks for a total weekly duration of 201 min, for approximately one to three walks over weekdays (Monday through Friday), as well as one to three walks on the weekend. The infant carrier was used by 22% of mothers at least half of the time during outdoor walks, and 18% reported a daily duration of infant carrying of one hour or more. Among other associations, infant and maternal enjoyment of outdoor walking correlated positively with the duration as well as the frequency of walking during weekdays and during the weekend. Furthermore, employed mothers walked for a shorter duration and less frequently on weekdays as compared to mothers on maternity leave or mothers without a paid job. The availability of nearby recreational areas correlated positively with the weekly duration and frequency of walks. The infant carrier was used more frequently during outdoor walks if more than one child lived in the household. Infant carrying during outdoor walks was also related to infant behavior at night. Roughly a third of the mothers (29%) regularly had their infant sleep outdoors for a weekly duration of four hours and a weekly frequency of approximately one to two times. Younger infants, infants of mothers with higher education and infants living in detached houses were more likely to be placed outdoors to sleep. Discussion. We identified associations of infant, maternal and environmental characteristics with outdoor time spent during infancy. These results lay the foundation for future research on the effects of the outdoors on child development as well as on facilitators and barriers for caregivers.

Our aims are 1) to assess whether sleeping problems persist from early childhood until adolescence, and 2) to investigate whether infant colic is associated with more sleeping problems throughout childhood and adolescence. Furthermore, we explore a moderation by parent-infant room sharing of potential associations between infant colic and sleeping problems. Data originate from a prospective longitudinal study in a healthy community sample (N = 185). Infant colic data were collected using cry diaries, filled in by the mothers for four days at age six weeks. The number of weeks of parent-infant room sharing from zero to six months of age were recorded using daily maternal diaries. Sleeping problems were assessed through maternal report at ages 2.5, 6 and 10 years, and child report at ages 12.5, 14 and 16.5 years. We used a score of Total Sleeping Problems, as well as subscales on Night Waking and Sleep Duration. Correlations were found between sleeping problems measured from 2.5 through 16.5 years for the Total Sleeping Problems, as well as for Night Waking and Sleep Duration. Compared to participants without infant colic, those with colic showed higher scores of Total Sleeping Problems between ages 12.5 and 16.5 years. We found no differences in sleeping problems between 2.5 and 10 years, nor evidence of a moderation by room sharing. Current findings suggest that sleeping problems developing in early and middle childhood persist throughout adolescence, and that children with infant colic may be prone to developing sleeping problems during adolescence.