Crying in the first 12 months of life: A systematic review and meta-analysis of cross-country parent-reported data and modeling of the "cry curve"

Validation of the Dutch Infant Crying and Parent Well-Being Screening Tool in Parents of Infants Less than 12 Months of Age

OBJECTIVE

To evaluate reliability and validity of the Dutch version of the Infant Crying and Parent Well-Being (ICPW) tool in identifying parents struggling with infant crying in the first year of life.

STUDY DESIGN

The original ICPW tool was translated into Dutch following established guidelines. The internal consistency and criterion validity of the Dutch ICPW tool were evaluated using a cross-sectional design. The translated ICPW tool and validated questionnaires on parental depression, stress, anxiety, and parenting balance were presented to parents of infants under 12 months during child health care visits and online.

RESULTS

The survey was completed by 488 parents, 400 mothers and 88 fathers. Of these, 172 participated after a child health care visit and 316 via online platforms. The Dutch ICPW showed satisfactory internal consistency (α = 0.69) and excellent criterion validity with parental mental health measures (r = 0.53-0.85). ICPW scores demonstrated positive correlations with parental depression, stress, and anxiety levels, and a negative correlation with parenting balance. Both mothers and fathers with a positive ICPW screen (≥3) reported significantly higher levels of parental mental health issues compared with those with a negative screen (P < .001). The ICPW was positive in 32% of the parents (n = 155), with consistent total scores regardless of the infant's increasing age (r = -0.024, P = .59). The ICPW tool exhibited a strong negative predictive value (93%) for diagnosing postpartum depression.

CONCLUSIONS

The Dutch ICPW tool is a reliable and valid screening instrument for identifying parents struggling with infant crying.

Comparative efficacy of probiotic mixture Bifidobacterium longum KABP042 plus Pediococcus pentosaceus KABP041 vs. Limosilactobacillus reuteri DSM17938 in the management of infant colic: a randomized clinical trial

We aimed to compare the efficacy of Bifidobacterium longum KABP042 + Pediococcus pentosaceus KABP041 (BL + PP) vs. Limosilactobacillus reuteri DSM17938 (LR) in alleviating the symptoms of infant colic, as commercially available formulations. A randomized, multicenter, parallel, single-blind (investigator) trial was conducted in 112 colicky infants diagnosed as per Rome IV criteria and randomly allocated to receive BL + PP orally (109 colony-forming units [CFU]/day, n = 55) or LR (108 CFU/day, n = 57) for 21 days. Primary study outcomes were percentage of responders (≥ 50% reduction in crying and fussing time from baseline, as reported by parents in a structured diary) and daily crying and fussing time (minutes/day) on days 7, 14, and 21 after randomization. Study groups were comparable at baseline. Responder rate was significantly higher in BP + PP group vs. LR group at days 7 (61.1% vs. 37.5%, p = 0.013) and 14 (84.6% vs. 59.3%, p = 0.004). Crying and fussing time (median [IQR]) became significantly lower in BL + PP group vs. LR group on day 7 (119 [60-210] vs. 180 [110-270]; p = 0.028), day 14 (60.0 [30-105] vs. 120 [60-180]; p = 0.017), and day 21 (29 [0-85] vs. 67 [30-165]; p = 0.011). No significant differences were found in the number of adverse events between the groups.

CONCLUSION

The specific formulation of B. longum KABP042 and P. pentosaceus KABP041 achieved a higher response rate and a larger reduction in crying and fussing time in colicky infants. Both probiotic interventions were well tolerated.

TRIAL REGISTRATION

The study was retrospectively registered as NCT05271747 on February 28th, 2022.

WHAT IS KNOWN

• L. reuteri DSM17938 (LR) is the most researched probiotic strain for infant colic against placebo in randomized, controlled clinical trials, and is recommended in various guidelines. A novel probiotic combining strains B. longum KABP042 and P. pentosaceus KABP041 (BL + PP) has also demonstrated efficacy in infant colic against placebo.

WHAT IS NEW

• This randomized study provides the first direct comparison of two probiotics for infant colic. BL + PP seems to be superior to LR in reducing crying time.

The development and validation of the beliefs about Baby Crying at Night (BBCN) scale

OBJECTIVE

What are young children trying to express when they cry at night? According to Sadeh, parental beliefs about why their child is crying may play a role in the development and persistence of their child's insomnia. The aim of this study was to create a scale that specifically assesses these parental interpretations in different dimensions.

METHODS

Children aged between 6 months and 3 years with either good sleep habits or behavioural insomnia were recruited. An initial, 20-item scale for the beliefs of why one's baby is crying at night was developed, with all items on a 7-point Likert span. The results of this scale from a large sample were then submitted to Exploratory (EFA) and confirmatory (CFA) factor analyses to converge on a final version and evaluate its psychometric properties and validity.

RESULTS

Among the 1009 subjects included in the analyses (46.2 % female, mean age: 1.63 ± 0.73, good sleepers n = 425 and bad sleepers n = 584). After the factor analysis was performed, a 14-item scale with 4 subscales quantifying each interpretation type resulted: namely, "Need for attachment" (5 items), "Need to cry before falling asleep" (3 items), "Leaving a child to cry during the night is traumatizing for the child" (4 items) and "Is in pain" (2 items). The CFA further confirmed an appropriate fit. The most divergent subscale between groups was the "Need for attachment" subscale.

CONCLUSION

This study proposes the first scale known to focus exclusively on parent interpretations of their child's night-time crying, without taking into account their nursing behaviours. It provides a clinical tool for more effectively discussing with parents, in order to address potential dysfunctional beliefs in the context of early childhood insomnia complaints, as well as a research tool for considering cognitive dimensions in the aetiology and treatment of behavioural insomnia.

An evaluation of the performance of stopping rules in AI-aided screening for psychological meta-analytical research

Several AI-aided screening tools have emerged to tackle the ever-expanding body of literature. These tools employ active learning, where algorithms sort abstracts based on human feedback. However, researchers using these tools face a crucial dilemma: When should they stop screening without knowing the proportion of relevant studies? Although numerous stopping rules have been proposed to guide users in this decision, they have yet to undergo comprehensive evaluation. In this study, we evaluated the performance of three stopping rules: the knee method, a data-driven heuristic, and a prevalence estimation technique. We measured performance via sensitivity, specificity, and screening cost and explored the influence of the prevalence of relevant studies and the choice of the learning algorithm. We curated a dataset of abstract collections from meta-analyses across five psychological research domains. Our findings revealed performance differences between stopping rules regarding all performance measures and variations in the performance of stopping rules across different prevalence ratios. Moreover, despite the relatively minor impact of the learning algorithm, we found that specific combinations of stopping rules and learning algorithms were most effective for certain prevalence ratios of relevant abstracts. Based on these results, we derived practical recommendations for users of AI-aided screening tools. Furthermore, we discuss possible implications and offer suggestions for future research.

Infant growth and tolerance with a formula based on novel native demineralized whey: A randomized double-blind pilot study

OBJECTIVES

The aim of the study was to evaluate the effects on infant growth and tolerance of a Test infant formula based on a novel whey extraction and demineralization process, compared to a Standard formula and a breastfed reference arm.

METHODS

Healthy term infants (n = 61) aged up to 21 days were randomized to Test or Control formula. A breastfed group (n = 39) served as a reference. Growth, tolerance, adverse events, and sleep were evaluated every month until 6 months of age. Plasma amino-acid concentrations at 3 months of age were measured in a subgroup population.

RESULTS

Growth curves of all infants globally agreed with World Health Organization standards across the 6-month period study. Regarding tolerance, no difference between the formula-fed groups was observed on daily number of crying episodes, intensity or time to onset of regurgitations, and stool frequency or consistency, except at 5 months with infants in the Control group having more watery stools. Plasma concentration of some amino acids differed between the groups, especially tryptophan concentration which was higher in infants fed with the Test formula. In parallel, total sleep duration was longer in these infants at 2, 3, and 5 months of age, corresponding to an increase in daytime sleep.

CONCLUSIONS

Test formula supported an adequate infant growth from birth to 6 months of age and was well-tolerated by all infants. An increase in total sleep at several months was also observed with the Test formula.

Infant colic and HPA axis development across childhood

This study examines the long-term impact of infant colic on Hypothalamic-Pituitary-Adrenal (HPA) axis development and the moderating role of attachment security, in a low-risk Dutch sample of 193 children. We assessed infant colic at 6 weeks, circadian cortisol concentrations at ages 1, 2.5, 6, and 10 years, and attachment security at 1 year. Findings indicated that infant colic was associated with steeper diurnal cortisol slopes and slightly higher cortisol concentrations throughout childhood. Attachment security did not moderate these associations. This is the first study to reveal a link between infant colic and the development of the HPA axis in healthy children beyond infancy. These findings have important implications for understanding early risk and protective factors in the stress system's development.

Pregnant women's autonomic responses to an infant cry predict young infants' behavioral avoidance during the still-face paradigm

Research suggests that women's autonomic nervous system responses to infant cries capture processes that affect their parenting behaviors. The aim of this study was to build on prior work by testing whether pregnant women's autonomic responses to an unfamiliar infant crying also predict their infants' emerging regulation abilities. Participants included 97 women in their third trimester of pregnancy, located in the United States. Most participants identified as White/non-Hispanic (48%) or Hispanic (30%), their mean age was approximately 30 years, and the modal family income was $40,000-$79,999. Pregnant women's respiratory sinus arrhythmia (RSA) and skin conductance levels (SCL)-which are thought to capture emotional engagement and behavioral inhibition, respectively-were measured while the women watched a relaxing video and a video of an unfamiliar infant crying. Approximately 7 months later, women and their infants completed the still-face paradigm (SFP). Infants' avoidance and resistance behaviors during the SFP reunions were rated. Pregnant women's RSA and SCL responses to the infant cry video uniquely predicted infants' avoidance (but not resistance) during the SFP. Infants displayed higher levels of avoidance when their mothers exhibited lower levels of RSA reactivity or when their mothers exhibited higher levels of SCL activity in response to the infant cry video. Maternal sensitivity during mother-infant free-play interactions did not mediate the associations between pregnant women's autonomic responses to the cry video and infants' avoidant behavior during the SFP. Discussion focuses on potential mechanisms underlying associations between pregnant women's autonomic responses to infant distress and infants' socioemotional development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Longitudinal changes in attention bias to infant crying in primiparous mothers

Introduction

Infant stimuli attract caregiver attention and motivate parenting behavior. Studies have confirmed the existence of attentional bias toward infant face stimuli; however, relatively little is known about whether attentional bias exists for infant cry stimuli, which are as important as faces in child-rearing situations. Furthermore, scarce longitudinal evidence exists on how attentional bias toward infant crying changes through the postpartum period.

Methods

In the present study, we conducted an experiment to assess bias toward infant crying at two postpartum time points: at Time 1 (Mean = 75.24 days), 45 first-time mothers participated and at Time 2 (Mean = 274.33 days), 30 mothers participated. At both time points, the mothers participated in a Stroop task with infant crying and white noise as the stimuli. They were instructed to answer the color out loud as quickly and accurately as possible, while ignoring the sound. Four types of audio stimuli were used in this task (the cry of the mother's own infant, the cry of an unfamiliar infant, white noise matched to the cry of the mother's own infant, and white noise matched to the cry of an unfamiliar infant), one of which was presented randomly before each trial. Response time and the correct response rate for each condition were the dependent variables.

Results

For response time, the main effect of familiarity was significant, with longer response times when the participant's infant's cry was presented. In addition, response times were lower at Time 2 than at Time 1 in some conditions in which crying was presented.

Discussion

The results suggest that mothers may be less disturbed by infant crying as they gain more experience. Elucidating the characteristics of postpartum mothers' changes in cognitive performance related to infants' cries would be useful in fundamental and applied research to understand the process of parents' adaptation to parenting.

The five "S's" and the "SNOO" Smart Sleeper-non-pharmacological interventions (NPI) to promote sleep and reduce crying of infants: a scoping review

Background

Sleeping and crying are normal activities of infants. Infant crying and night wakings can be both distressing and exhausting for parents. At its worse it may be associated with an increased risk of maternal depression and psychosocial stress for both parents. Strategies for reducing crying and improving sleep include the five "S's"-swaddling, side/stomach position, sucking, swinging and shushing sounds simulating "womb-like" sensations. The "SNOO" Smart Sleeper (SNOO), a "smart" bassinet, incorporates 3 of the five "S's", swaddling, swinging (rocking) and emits soothing sounds while demonstrating safe infant sleep practices. This paper explores the effectiveness of the five "S's" and the SNOO.

Methods

References for the five "S's" were obtained from various sources while a scoping review of publications from PubMed, Embase and Web of Science was undertaken to seek out relevant studies to document the efficacy of the SNOO.

Results

The five "S's" appear to help soothe infants, reduce their crying and improve their sleep. In addition, infant obesity rates fell. Infants also experienced less pain following immunisations. Of the 66 papers gleaned from the database in mid-2021 for the scoping review, only those which provided clear outcomes and conclusions, were complete and related to infants were included. That resulted in only 2 studies that fitted the criteria imposed. They suggested that the SNOO incorporating 3 of the five "S's" had similar beneficial effects.

Conclusions

The five "S's" were effective non-pharmacological strategies to help reduce crying and improve sleep in infants. Confounding factors included normal crying of infants, triggers of hunger or tiredness, or recognised causes of crying. The 2 studies reviewed suggested that the SNOO was helpful in reducing crying and improving the sleep duration of normal infants. Further studies have suggested it may be used therapeutically for distressed or ill infants.

The dark side of fear expression: Infant crying as a trigger for maladaptive parental responses

While infant fearfulness, and its expression via crying, may have been adaptive in our evolutionary history, for modern parents, crying can be challenging to respond to. We discuss how and why prolonged crying can raise the risk for difficulties with adult care. Given that crying is the most-reported trigger for shaking, its potential to elicit maladaptive responses should not be overlooked.

Infant crying predicts real-time fluctuations in maternal mental health in ecologically valid home settings

Exposure to infant crying is a well-established predictor of mothers' mental health. However, this association may reflect many potential mechanisms. Capturing dynamic fluctuations in mothers' states simultaneously with caregiving experiences is necessary to identify the real-time processes influencing mental health. In this study, we leveraged ecological momentary assessments (EMAs) and infant-worn audio recorders to capture variability in mothers' mental health symptoms and their exposure to infant crying over one week in a racially and socio-economically diverse urban North-American sample (N = 53). We use multilevel modeling to characterize within- and between-person effects of crying on maternal negative affect and symptoms of depression and anxiety. Within participants, when infants cried more than average in the 10 min, 1 hr, and 8 hr prior to an EMA report, mothers' negative affect subsequently increased, controlling for mean levels of infant crying. In contrast to findings from laboratory studies, in everyday settings crying exposure did not immediately increase feelings of depression. Only when crying was above average for 8 hr prior to EMA did mothers report increases in subsequent depression symptoms, suggesting that the effects of crying on maternal mental health take hours to unfold in ecologically valid home settings. Between participants, mothers of infants who cried more on average did not report higher negative affect or symptoms of depression or anxiety. Overall, our findings reveal that crying exposure dynamically influences maternal negative affect and depression but not anxiety in ecologically valid real-world settings. (PsycInfo Database Record (c) 2023 APA, all rights reserved).