Investigating skin-to-skin care patterns with extremely preterm infants in the NICU and their effect on early cognitive and communication performance: a retrospective cohort study

Abstract

Objectives: The primary objective of the study was to investigate how patterns of skin-to-skin care might impact infant early cognitive and communication performance.

Design: This was a retrospective cohort study.

Setting: This study took place in a level-IV all-referral neonatal intensive care unit in the Midwest USA specialising in the care of extremely preterm infants.

Participants: Data were collected from the electronic medical records of all extremely preterm infants (gestational age <27 weeks) admitted to the unit during 2010-2011 and who completed 6-month and 12-month developmental assessments in the follow-up clinic (n=97).

Outcome measures: Outcome measures included the cognitive and communication subscales of the Bayley Scales of Infant Development, Third Edition (Bayley-III); and skin-to-skin patterns including: total hours of maternal and paternal participation throughout hospitalisation, total duration in weeks and frequency (hours per week).

Analysis: Extracted data were analysed through a multistep process of logistic regressions, t-tests, χ² tests and Fisher's exact tests followed with exploratory network analysis using novel visual analytic software.

Results: Infants who received above the sample median in total hours, weekly frequency and total hours from mothers and fathers of skin-to-skin care were more likely to score ≥80 on the cognitive and communication scales of the Bayley-III. However, the results were not statistically significant (p>0.05). Mothers provided the majority of skin-to-skin care with a sharp decline at 30 weeks corrected age, regardless of when extremely preterm infants were admitted. Additional exploratory network analysis suggests that medical and skin-to-skin factors play a parallel, non-synergistic role in contributing to early cognitive and communication performance as assessed through the Bayley-III.

Conclusions: This study suggests an association between early and frequent skin-to-skin care with extremely preterm infants and early cognitive and communication performance.

Keywords: NEONATOLOGY; extreme prematurity.

Figure 1

Overall and parent-specific SSC participation: boxplots displaying the distribution of overall SSC participation and by parent. Thick horizontal lines give medians while boxes display the middle 50% of the data (25th and 75th centiles). Whiskers extend to no more than 1.5 times the IQR (IQR= difference between 75th and 25th centiles) from the edge of the box. Points beyond the whiskers represent outliers. SSC, skin-to-skin care.

Figure 2

Total SSC hours per week. Blue line displays the total number of SSC hours per week for all families in the study, by postmenstrual age. Red line gives the total number of babies in the NICU for the given week. NICU, neonatal intensive care unit; SSC, skin-to-skin care.

Figure 3

SSC intensity (hours per week per family). Blue line displays the average SSC intensity (hours per family per week) by postmenstrual age. Red line gives the total number of babies in the NICU for the given week. NICU, neonatal intensive care unit; SSC, skin-to-skin care.

Figure 4

Bayley Cognitive and Communication Scores by SSC participation: boxplots displaying the distribution of Bayley cognitive, communication and combined cognitive–communication (Cog–Comm) scores at 6 and 12 months by SSC participation (high vs low). High SSC participation was defined as having above the median participation for total SSC hours, mother SSC hours, father SSC hours and SSC intensity (see text for details). Thick horizontal lines give medians while boxes display the middle 50% of the data (25th and 75th centiles). Whiskers extend to no more than 1.5 times the IQR (IQR= difference between 75th and 25th centiles) from the edge of the box. Points beyond the whiskers represent outliers.

Figure 5

Visual analytical display from StickWRLD software. The visual space is divided into three main regions: medical factors, skin-to-skin factors and Bayley-III Scores. Each line represents a significant correlation between factors with stronger correlations represented by lines that are thicker in diameter. Line colours are assigned randomly and are used only to aid in visual comparisons of associations. Within-region correlations are evident and expected. Two blue arrows indicate two unexpected strong correlations (one from each region) that converge on the Bayley-III 12-Month Cognitive Score, suggesting skin-to-skin Care frequency and presence or absence of intraventricular haemorrhage (IVH) as parallel, but non-interactive factors impacting the score.