Infant Sleep Research Articles

Brazilian Mother’s Practice on Infant Body Position From Birth to 6 Months Old

There is a gap in the understanding of what has been recommended by health professionals to Brazilian mothers regarding infant body positioning whereas the description of this parenting practice can provide criteria for guidance programs already in the maternity ward. This study aimed to record the time (hours/day) Brazilian mothers reported that their infants spent awake or sleeping in 1 of the four body postures: Prone, supine, lateral positions and sitting. The second aim of this study was to verify whether this reported time was associated with birth weight, gestational age, infant chronological age and maternal age. A cross sectional study assessed 92 mothers divided into six groups according to the age of their full-term infant, in months (Mth): 1 Mth (n= 15), 2 Mth (n= 15), 3 Mth (n= 15), 4 Mth (n= 15), 5 Mth (n= 17), and 6 Mth (n= 15). Mothers registered in a 24-hour schedule the most frequent positioning of each infant in 1 day based on the week prior to the assessment day. Infant chronological age was associated with time spent in positions reported by mothers (p< .05). 47.8% of mothers stated not placing infants in prone position anytime in the awake period. Some mothers reported that the infant slept in the prone position. Brazilian caregivers still need to be alerted that the practice of not placing infants to lay in prone might hinder developmental opportunities for them, as well as, on the risks of SIDS and the importance of supine position for infants to sleep.

Assessing infant sleep practices and other risk factors of SIDS in Zambia: a cross-sectional survey of mothers in Lusaka, Zambia

BackgroundHaving infants sleep with their parents and sleeping face down or on their sides are the two most proximate and modifiable risk factors for sudden infant death syndrome (SIDS). Little is known about the burden of SIDS or the prevalence of these risk factors in Africa. Our primary objective was to determine the prevalence of modifiable risk factors of SIDS in Lusaka, Zambia.MethodsWe conducted cross-sectional surveys with recent mothers of infants aged < 1 year across two busy urban clinic sites in Lusaka, Zambia. We used log-binomial regression analysis to identify factors predictive of bedsharing and prone sleeping.ResultsSurveys were conducted with 478 mothers between April-May 2021. The sleep-related risk factors, bedsharing and side sleeping, were widely prevalent. 89.5% of respondents indicated that they share a bed with the infant during sleep, 73.0% preferred putting their baby on its side, and 19.9% preferred the prone position. Only 6.7% of respondents described using the safer, supine position. Age of infant was the only factor which was predictive of prone sleeping. Infants > 2 months old were twice as likely to be put to sleep in a prone position compared to infants aged less than 2 months old. Mothers reported that they rarely (24.1%) received advice from medical caregivers to use the supine position. Maternal use of alcohol (12.0%) and tobacco (0.8%) during pregnancy were uncommon.ConclusionsBedsharing and placing the infant to sleep on the side were commonly reported among the mothers we interviewed. Whether this represents an opportunity to reduce SIDS in Zambia is unclear since accurate data on the burden of SIDS in Zambia is not available. There is a need for increased awareness of SIDS and more prospective data collection on its burden and related risk factors in these African populations.

Systematic Review of the Effects of Sleep on Memory and Word Learning in Infancy

AbstractThis systematic review surveyed research on the associations between sleep and the memory processes involved in word learning in infancy. We found only 16 studies that addressed this topic directly, identifying associations between infant sleep and the memory processes, the identification of word forms in running speech, and the stabilization and generalization of new word form–meaning associations. Some studies investigated changes in brain responses after word learning and in sleep parameters during postlearning sleep. Others investigated the long‐term effects of sleeping patterns on later vocabulary development. All but one of these studies identified positive associations between sleep and word learning in early childhood, extending similar findings from studies on adults and school‐aged children. However, there remain several gaps in the current research on early lexical development and sleep. Future investigations should address these gaps for researchers to better understand lexical development and to create links between memory and language acquisition research.

Implementation of Behavioral Interventions for Infant Sleep Problems in Real-World Settings

To compare the real-world frequency, timing, duration, difficulty, and helpfulness of 3 infant Behavioral Sleep Intervention (BSI) approaches: Unmodified Extinction, Modified Extinction, and Parental Presence and to examine the effectiveness and safety of these approaches by comparing infant sleep, parent sleep, daytime sleepiness, depression, and parent-infant bonding between parents who had and had not implemented these interventions. Participants were 2090 parents (75% mothers, 79% White/Caucasian) of US infants (49% girls) aged 3-18months (M=9.1, SD=4.1). Parents completed online questionnaires regarding their infant's sleep, their own sleep, daytime sleepiness, depression levels, and parent-infant bonding. Infant sleep was assessed via objective-albeit exploratory-autovideosomnography data obtained from the 14 days prior to survey completion. Sixty-four percent of parents reported implementing BSIs. The average age at intervention was 5.3months (SD=2.6). Unmodified and Modified Extinction were rated as significantly more difficult to implement compared with Parental Presence but also as more helpful, shorter, and quicker to show improvements. Infant nighttime sleep was longer and more consolidated in the Unmodified and Modified Extinction groups compared with the Parental Presence and non-BSI groups. No differences were found between BSI groups in parent sleep, sleepiness, depression, or parent-infant bonding. Implementation of BSIs outside clinical settings is pervasive and occurs earlier than generally recommended. Unmodified and Modified Extinction were associated with longer and more consolidated infant sleep. Despite concerns regarding the potential harm of BSIs, implementation of these approaches was not linked with negative outcomes, providing additional evidence for their safety and effectiveness.

Infant Safe Sleep in the District of Columbia: Better for Both.

Sudden unexpected infant death (SUID) rates within the District of Columbia (DC) vary, with rates 3 times higher in certain geographical areas than the cumulative rate in DC and 7 times higher than the national rate. The majority SUIDs are due to unsafe sleep practices. Although safe sleep education and resources are available in these areas, the high sleep-related infant mortality suggests unmet barriers to infant safe sleep. We sought to investigate potential contributions to local infant mortality through focus groups regarding infant sleep practices among DC caregivers. In this qualitative study, caregivers were probed regarding barriers and facilitators of infant sleep practices. Data were collected until thematic saturation was reached, then coded. Themes were developed and revised in an iterative manner. Fifteen caregivers participated in three focus groups. Themes included sources of infant sleep knowledge, challenges for infant sleep, and motivators for infant sleep choice. All caregivers reported knowledge of safe sleep practices. Infant sleep practices varied, and included unsafe practices such as bed sharing, co-sleeping, and use of swings or bouncers for infant sleep. Challenges of adhering to safe sleep practices included infant needs, competing family demands, the overwhelming nature of newborn sleep, threats, and conflicting information. Motivators for infant sleep practices included better sleep, convenience, safety, tradition, and needs of the infant and caregiver. Although caregivers report knowledge of safe sleep recommendations, actual infant sleep practices vary and include unsafe sleep practices. More focused interventions are needed to address this gap between safe sleep knowledge and practice.

Validation of the sleep disturbance scale for children (SDSC) in infants and toddlers from mainland China.

This study is to evaluate the reliability and validity of SDSC among infants (aged 6-36 months), and to provide a reference for expanding the application of the SDSC for Chinese infants (SDSC-I). From April to November 2021, parents of infants from Fuzhou, Quanzhou, Longyan, Sanming, and Nanping cities in Fujian Province, China completed the SDSC-I. Several factor analyses were performed to evaluate the reliability and validity of the scale. Of note, 432 out of 469 samples were valid. After item selections and exploratory factor analyses, the SDSC-I concluded six dimensions (disorders of initiating sleep, disorders of maintaining sleep, sleep hyperhidrosis, sleep breathing disorders, parasomnias, and non-restorative sleep and excessive somnolence) with 23 items. The Cronbach's α coefficient of the scale was 0.863, and those for the six dimensions were within 0.576-0.835. The values of parameters for content validity of the scale were: IR = 0.87, I-CVI > 0.78, Kappa value > 0.74, S-CVI/UA = 0.87, S-CVI/Ave = 0.98. Principal component analysis revealed that the Kaiser-Meyer-Olkin (KMO) value was 0.84, and the factor loading of items ranged from 0.328 to 0.849, with six factors of eigenvalue more than one, which could explain 58.274% of the total variance. The confirmatory factor analysis results showed that χ2/DF was 3.556, root-mean-square error of approximation (RMSEA) was 0.077, comparative fit index (CFI) was 0.809, and standardized RMR (SRMR) was 0.070. Our study provides evidence that the SDSC-I is reliable and valid, and it is effective for the screening and management of sleep disturbances among infants (aged 6-36 months). Compared with other questionnaires such as the Brief Infant Sleep Questionnaire (BISQ), it is worthy of popularization and application in pediatric primary care.

Trajectories of reported sleep duration associate with early childhood cognitive development.

Examine how different trajectories of reported sleep duration associate with early childhood cognition. Caregiver-reported sleep duration data (n = 330) were collected using the Brief Infant Sleep Questionnaire at 3, 6, 9, 12, 18, and 24 months and Children's Sleep Habits Questionnaire at 54 months. Multiple group-based day-, night-, and/or total sleep trajectories were derived-each differing in duration and variability. Bayley Scales of Infant and Toddler Development-III (Bayley-III) and the Kaufman Brief Intelligence Test- 2 (KBIT-2) were used to assess cognition at 24 and 54 months, respectively. Compared to short variable night sleep trajectory, long consistent night sleep trajectory was associated with higher scores on Bayley-III (cognition and language), while moderate/long consistent night sleep trajectories were associated with higher KBIT-2 (verbal and composite) scores. Children with a long consistent total sleep trajectory had higher Bayley-III (cognition and expressive language) and KBIT-2 (verbal and composite) scores compared to children with a short variable total sleep trajectory. Moderate consistent total sleep trajectory was associated with higher Bayley-III language and KBIT-2 verbal scores relative to the short variable total trajectory. Children with a long variable day sleep had lower Bayley-III (cognition and fine motor) and KBIT-2 (verbal and composite) scores compared to children with a short consistent day sleep trajectory. Longer and more consistent night- and total sleep trajectories, and a short day sleep trajectory in early childhood were associated with better cognition at 2 and 4.5 years.

Supplemental Material for Indirect Associations Between Infant Sleep, Parental Sleep, and Sexual Well-Being in New Parent Couples

Supplemental Material for Indirect Associations Between Infant Sleep, Parental Sleep, and Sexual Well-Being in New Parent Couples

Residential parenting services: An integrative literature review of characteristics, service usage and parent and staff perspectives.

The primary aim of the review was to provide an overall assessment of residential parenting services in Australia, by describing the characteristics of infants and parents using residential parenting services, their prior service use and reasons for admission, referral pathways for access and parenting and infant outcomes. The secondary aims were to explore parent and staff perception of the programmes. An integrative literature review. A systematic and comprehensive search of health and social sciences databases was conducted for studies related to residential parenting services (published between 1st January 1990-31st December 2019). Six hundred and eleven peer-reviewed papers were identified, after which 301 duplicates were removed and an additional 256 papers excluded after titles/abstracts were read. Of the remaining 54 abstracts/papers, a further 14 were omitted as not relevant. Forty papers were independently reviewed by four authors. ENTREQ and MOOSE checklists were applied. Thirty studies were quantitative, nine were qualitative, and one was mixed methods. All studies originated from in Australia. Women and babies admitted to residential parenting services were found more likely to be: older, Australian born, from higher socio-economic groups, and first-time mothers, and having labour and birth interventions and a history of mental health disorders. The babies were more likely to be twins, male and admitted with sleep disorders and dysregulated behaviour. Studies reporting postintervention outcomes demonstrated improvements to maternal mental health, breastfeeding, parenting confidence and sleep quality, and infant sleeping and behaviour.

The outcomes of a healing environment and clustering nursing care on premature infants' vital signs, pain, and sleeping

Our study aimed to assess the effects of creating a healing environment and clustering nursing care on premature infants' vital signs, pain, and sleeping. The study had an experimental research design for the control and study group, each with 53 premature infants. We collected the data through the Vital Signs Sheet, Premature Infant Pain Profile, and Neonatal behavioral state. We used T-tests and chi-square tests to assess the differences between groups. There was a highly statistically significant difference between the study and control groups concerning respiration (p-value<0.01) and heart rate, systolic blood pressure, and O2 saturation (p-value<0.05). 90.6% of participants in the study group had a mild total premature infant pain profile, while 37.7% of the control group had a moderate total premature infant pain profile score. Applying a healing environment and clustering nursing care significantly improved respiration, heart rate, oxygen saturation, and systolic blood pressure. Furthermore, it increased sleep time and decreased wake state and pain score.

Survey of Korean daycare personnel on safe sleep practices related to sudden unexplained infant death: a cross-sectional exploratory study.

Safe sleep practices (SSP) are among the main strategies to reduce sleep-related sudden unexplained infant death (SUID). Daycare personnel must be knowledgeable and trained in SSP related to SUID. This study explored the experience, knowledge, and confidence regarding SSP associated with SUID of daycare personnel. A cross-sectional survey was conducted with 395 staff members at 61 daycare centers to measure their experience related to SSP (10 items), related to sleep position and location, bedding materials, and other topics; knowledge of SSP (18 items); and confidence in SSP (1 item) related to SUID. A substantial proportion (23.6%) of respondents used the lateral or prone positions for infant sleep. On average, 4.5 bedding materials were used for infant sleep. Participants showed a lack of knowledge about SSP as indicated by a 56.6% knowledge of SSP related to SUID correct answer rate. Personnel who received SUID education were more knowledgeable and had more confidence regarding SSP than those who did not. More knowledge and confidence related to SSP were associated with better adherence to SSP. Standard SSP guidelines should be developed based on South Korea's culture of childcare for educating both childcare professionals and parents at home.

NREM–REM alternation complicates transitions from napping to non-napping behavior in a three-state model of sleep–wake regulation

The temporal structure of human sleep changes across development as it consolidates from the polyphasic sleep of infants to the single nighttime sleep episode typical in adults. Experimental studies have shown that changes in the dynamics of sleep need may mediate this developmental transition in sleep patterning, however, it is unknown how sleep architecture interacts with these changes. We employ a physiologically-based mathematical model that generates wake, rapid eye movement (REM) and non-REM (NREM) sleep states to investigate how NREM–REM alternation affects the transition in sleep patterns as the dynamics of the homeostatic sleep drive are varied. To study the mechanisms producing these transitions, we analyze the bifurcations of numerically-computed circle maps that represent key dynamics of the full sleep–wake network model by tracking the evolution of sleep onsets across different circadian (∼ 24 h) phases. The maps are non-monotonic and discontinuous, being composed of branches that correspond to sleep–wake cycles containing distinct numbers of REM bouts. As the rates of accumulation and decay of the homeostatic sleep drive are varied, we identify the bifurcations that disrupt a period-adding-like behavior of sleep patterns in the transition between biphasic and monophasic sleep. These bifurcations include border collision and saddle–node bifurcations that initiate new sleep patterns, period-doubling bifurcations leading to higher-order patterns of NREM–REM alternation, and intervals of bistability of sleep patterns with different NREM–REM alternations. Furthermore, patterns of NREM–REM alternation exhibit variable behaviors in different regimes of constant sleep–wake patterns. Overall, the sequence of sleep–wake behaviors, and underlying bifurcations, in the transition from biphasic to monophasic sleep in this three-state model is more complex than behavior observed in models of sleep–wake regulation that do not consider the dynamics of NREM–REM alternation. These results suggest that interactions between the dynamics of the homeostatic sleep drive and the dynamics of NREM–REM alternation may contribute to the wide interindividual variation observed when young children transition from napping to non-napping behavior.

Impact of the Finnish Maternity Grant on infant mortality rates in the 20th century: a natural experimental study

BackgroundBaby boxes provide goods to new parents and a space for infant sleeping. They were first introduced in Finland, and it has been argued that the policy helped reduce infant...

Modeling of infant safe sleep practice in a newborn nursery: a quality improvement initiative

Sudden infant death syndrome (SIDS) is a leading cause of infant mortality in the US. The American Academy of Pediatrics has provided recommendations for infant sleeping position and environment to decrease SIDS rates. These recommendations reinforce the importance of modeling safe sleep practices in the newborn nursery. Although many quality improvement initiatives have been undertaken to improve safe sleep in the nursery, such efforts are sparse in low-volume birth hospitals. This project aimed to improve infant sleep practices in a 10-bed level I nursery using visual cues (crib cards) and nursing education. We defined “safe sleep practice” if a newborn slept in a safe position in a flat bassinet and in a safe environment. We measured safe sleep practices before and after the intervention using an audit tool. As a result, safe sleep practices improved from 32% (30/95) preintervention to 75% (86/115) postintervention (P < 0.01). This study demonstrates that implementing a quality improvement initiative to improve infant sleep practices in a low-volume nursery is feasible and impactful.

Associated factors of breastfeeding practices among mothers in rural Vietnam: A community-based study

PurposeTo examine the factors associated with the early initiation of breastfeeding and exclusive breastfeeding among mothers in Vietnam during the first 6 months postpartum. Design and methodsA cross-sectional study including 200 mother-infant dyads was conducted at community health stations. Information on demographic characteristics, modes of delivery, infant sleep problems, and breastfeeding practices was collected using structured questionnaires. The main independent variable of social support was assessed using the Multidimensional Scale of Perceived Social Support. Multivariable logistic regression analysis was used. ResultsAmong the study cohort, 37.5% of mothers had initiated breastfeeding within 1 h after birth, and 27.5% continued exclusive breastfeeding for the first 6 months postpartum. Mothers living in urban areas or who had undergone cesarean delivery were less likely to have initiated breastfeeding within 1 h after birth (p < 0.05). The odds of exclusive breastfeeding were lower among infants with longer waking hours at night (≥4 h) and sleep problems (p < 0.05). Support from the mother's significant other and friends was significantly associated with exclusive breastfeeding (p < 0.05). ConclusionsEarly initiation of breastfeeding and exclusive breastfeeding were not common in a community sample of Vietnamese mothers. Identifying and assessing mothers who lack breastfeeding support is necessary to promote and sustain breastfeeding practices. Practice implicationFurther comprehensive breastfeeding interventions and support are needed for postpartum women in Vietnam.

Links between Daytime Napping, Night-Time Sleep Quality and Infant Attention: An Eye-Tracking, Actigraphy and Parent-Report Study.

The current study explored the potential influence of infant sleep, measured by parental report and actigraphy, and family functioning on attention development using eye tracking. The use of actigraphy in parallel with parental report, has the advantage of measuring participant's sleep throughout the night without parental observation and the ability to objectively assess sleep quality. An eye-tracking version of the Gap-Overlap task was used to measure visual attention. Questionnaires and behavioural assessment were used to assess family function, and general cognitive development. Fifty infants (Mean age = 13.44 months, SD = 3.10) participated in the study, 23 of which had full final datasets. Results show that daytime sleep duration, as measured by parental report, and proportion of light sleep at night, as measured by actigraphy, are linked to visual attention. A higher proportion of light sleep, a marker of poorer sleep quality, and less daytime sleep were negatively linked with facilitation and disengagement on the Gap-Overlap task. Family functioning was not associated with attention. The results provide initial evidence that in addition to the amount of daytime sleep; quality of night-time sleep as measured by proportion of light sleep, is a potentially useful sleep variable which requires further focus in the study of attention development.

Sleep patterns of infants and young children and their association with breastfeeding: a study based on K-means clustering

To investigate the sleep patterns and characteristics of infants and young children and the association between sleep patterns and breastfeeding. A general information questionnaire, Brief Infant Sleep Questionnaire (BISQ), and a questionnaire on feeding were used to investigate the sleep quality and feeding patterns of 1 148 infants and young children aged 7-35 months. The K-means clustering method was used to identify sleep patterns and characteristics. A multivariate logistic regression analysis was used to investigate the association between sleep patterns and breastfeeding. Three typical sleep patterns were identified for the 1 148 infants and young children aged 7-35 months: early bedtime and long sleep time; short sleep latency and moderate sleep time; late bedtime, prolonged sleep latency, and insufficient sleep time. The third pattern showed sleep disorders. The multivariate logistic regression analysis showed that compared with formula feeding, exclusive breastfeeding within 6 months after birth reduced the risk of sleep disorder patterns by 69% (OR=0.31, 95%CI: 0.11-0.81). The risk of sleep disorder patterns was reduced by 40% (OR=0.60, 95%CI: 0.38-0.96) in the infants receiving breastfeeding for 4-6 months compared with those receiving breastfeeding for 1-3 months. There are different sleep patterns in infants and young children, and breastfeeding can reduce the development of sleep disorder patterns.

Outcomes of Childbirth Education in PRAMS, Phase 8.

To determine if childbirth education is associated with improved outcomes for national maternal child health goals in the United States. This was a secondary analysis of PRAMS data. The sample was limited to survey respondents who answered a question "During your most recent pregnancy, did you take a class or classes to prepare for childbirth and learn what to expect during labor and delivery?" The outcomes included nine national objectives from Title V and Healthy People. Logistic regression models were built with control for characteristics associated with attending childbirth education. Odds ratios were converted to adjusted risk ratios for interpretation. Stratification by maternal race/ethnicity and use of Medicaid identified opportunities for improvement in childbirth education. Of the 2,256 eligible respondents, 936 (41.5%) attended childbirth education. Attending childbirth education was associated with reduced likelihood of primary cesarean (ARR 0.79), increased attendance at postpartum visit (ARR 1.06), use of birth control (ARR 1.07), safe infant sleep (Back to Sleep ARR 1.04; Sleep on Own 1.12), and breastfeeding (Ever breastfeed ARR 1.08; still breastfeeding ARR 1.15). No association was found for LARC use or postpartum depression. Not all benefits of childbirth education were apparent for all racial/ethnic groups, nor for those with Medicaid insurance. Childbirth education is a community intervention that may help achieve population maternal and child health goals.

Relationships between screen viewing and sleep quality for infants and toddlers in China: A cross-sectional study.

AimCurrently young children have more opportunity to access all kinds of media, while their sleep duration has been steadily decreasing. However, little is known about the relationships between screen viewing and sleep quality, and the reasons of screen viewing for children under three years old in China. This study aimed to describe the relationships between screen viewing and sleep quality of infants and toddlers in mainland China.MethodsA cross-sectional study was conducted. Eight hundred twenty-seven children were recruited at a health care unit from a university affiliated hospital in China, and the questionnaires were completed by their parents. An extended Brief Infant Sleep Questionnaire and a Screen Viewing Questionnaire were used to collect information on children's sleep quality and screen viewing. Multivariate linear regression models were used to assess the relationships between screen viewing and sleep quality among infants and toddlers, adjusted for sociodemographic variables.ResultsOf the 827 children, 26.9% of the infants and 61.4% of the toddlers did not comply with the World Health Organization (WHO) guideline on screen time. Even after adjusting for the sociodemographic covariates for both infants and toddlers, negative relationships between screen time and total sleep time (P < 0.001), and screen time and nighttime sleep (P < 0.001) existed. TV viewing time was negatively related to infants' total sleep time (β = −0.15, P < 0.001) and toddlers' nighttime sleep (β = −0.1, P < 0.05). Smartphone viewing time was negatively related to toddlers' total sleep time (β = −0.12, P < 0.05) and daytime sleep (β = −0.22, P < 0.05). Parents who offered screen media for children when they needed to do house chores were more likely to report that their children had less total sleep time (β = −0.1, P < 0.05) and shorter longest sleep episode (β = −0.1, P < 0.05).ConclusionThe majority of toddlers did not meet the WHO guidelines on screen time in China. Screen time was negatively related to total sleep time and nighttime sleep among infants and toddlers. Practical strategies, such as education programs on children's screen viewing, more outdoor exercises and indoor parent-child activities, providing other educational materials instead of screening, early sleep, restricted use of TVs and smartphones, and screen co-viewing, are needed to improve young children's sleep quality and promote their development.

PENGARUH KONSELING SLEEP HYGIENE DALAM MENINGKATKAN KUALITAS TIDUR ANAK USIA 3-24 BULAN

Sleep problems in childhood have been found to be associated with memory and learning impairments, irritability, difficulties in mood modulation, attention and behavioral problems, hyperactivity and impulsivity. Short sleep duration has been found to be associated with overweight and obesity. This research describes the protocol of a behavioral intervention planned to promote healthier sleep in infants. Methods: The study is a 1:1 parallel group single-blinded randomized controlled trial enrolling a total of 24 infants at 3-24 months of age. The main eligibility criterion is the infant’s sleep lasting on average less than 15 h per 24 h (daytime and nighttime sleep). The main outcome assessed is the between group difference in average nighttime self-regulated sleep duration (the maximum amount of time the child stays asleep or awake without awakening the parents), at ages 6, 12 and 24 months, evaluated by means of activity diary records and questionnaires. Result: The negative impact of inadequate and insufficient sleep on children’s physical and mental health are unquestionable, as well as its impact on cognitive function, academic performance and behavior. It is hoped that this study will demonstrate a beneficial effect on children's sleep behavior.