Early life attachment in term and preterm infants

Background Preterm birth is associated with atypical cognitive and socioemotional outcomes in childhood. Secure infant attachment protects against adverse outcomes, but could be modified by alterations in the early caregiving environment inherent to essential neonatal intensive care or co-morbidities of preterm birth. We aimed to test the hypothesis that preterm birth is associated with differences in infant attachment, and to investigate clinical, neurodevelopmental and socioeconomic variables that are associated with infant attachment. Methods 82 preterm and 75 term infants with mean (range) gestational age at birth 29.5 (22.1 – 32.9) and 39.6 (36.4 – 42.1) weeks, respectively, completed the Still-Face Paradigm (SFP) at nine months of corrected age. Attachment dimensions and categories were obtained from infant responses to the SFP during the reunion episode using a published coding scheme, and an alternative principal component (PC) and clustering strategy. Neurodevelopment was assessed using the Vineland Adaptive Behavior Scales, and socioeconomic status was operationalized as neighborhood deprivation. Results Preterm and term infants significantly differed in fretfulness, attentional PC scores and in their distribution between attachment clusters (p-values ≤ 0.3); with preterm infants exhibiting less fretful and more neutral responses to the SFP. Preterm and term infants did not significantly differ in distress, attentiveness to caregivers, emotional PC scores, or in their distribution between attachment styles (p-values ≥ .13). In the whole sample, fretfulness correlated with socioeconomic deprivation (rs = −0.18, p-value = .02). Conclusions Data reveal subtle attachment differences between preterm and term infants at nine months of age, which may not always be captured by traditional approaches for categorizing attachment. Findings suggests that caregiver-infant attachment relationships may not be fully resilient to the effects of prematurity on the developing infant, but this depends on how attachment is measured. Our results highlight putative links between socioeconomic deprivation and infant attachment that warrant further study. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was funded, in part, by the Wellcome Trust [Grant No. 108890/Z/15/Z]. For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. LJ-S is supported by the University of Edinburgh Wellcome Trust Translational Neuroscience 4-year PhD programme (Grant No. 108890/Z/15/Z). This work was supported by Theirworld (http://www.theirworld.org) and was carried out in the MRC Centre for Reproductive Health [MRC G1002033]. The funding sources had no role in the study design, execution, analysis, interpretation of the data, decision to publish or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval was obtained from the National Research Ethics Service (16/SS/0154), South East Scotland Research Ethics Committee, and NHS Lothian Research and Development (2016/0255). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data availability is governed in accordance with the Theirworld Edinburgh Birth Cohort data access and collaboration policy, which is available on request * AA : Attentive-Avoidant scale GA : Gestational age at birth HD : Happy-Distressed scale ICC : Intraclass correlation coefficient NFF : Not fretful-Fretful scale NICU : Neonatal Intensive Care Unit PC : Principal component PC1 : First principal component PC2 : Second principal component SD : Standard deviation SIMD : Scottish Index of Multiple Deprivation SFP : Still-Face Paradigm VABS : Vineland Adaptive Behavior Scales