The association between infant salivary cortisol and parental presence in the neonatal intensive care unit during and after COVID-19 visitation restrictions: A cross-sectional study

Abstract

Objectives: Parent-infant interaction in the neonatal intensive care unit (NICU) promotes health and reduces infant stress. During the COVID-19 pandemic, however, NICUs restricted parent-infant interaction to reduce viral transmission. This study examined the potential relationship between pandemic visitation restrictions, parental presence and infant stress as measured by salivary cortisol.

Methods: A two-NICU cross-sectional study of infants with gestational age (GA) 23-41 weeks, both during (n = 34) and after (n = 38) visitation restrictions. We analysed parental presence with and without visitation restrictions. The relationship between infant salivary cortisol and self-reported parental NICU presence in hours per day was analysed using Pearson's r. A linear regression analysis included potential confounders, including GA and proxies for infant morbidity. The unstandardised B coefficient described the expected change in log-transformed salivary cortisol per unit change in each predictor variable.

Results: Included infants had a mean (standard deviation) GA of 31(5) weeks. Both maternal and paternal NICU presence was lower with versus without visitation restrictions (both p ≤0.05). Log-transformed infant salivary cortisol correlated negatively with hours of parental presence (r = -0.40, p = .01). In the linear regression, GA (B = -0.03, p = .02) and central venous lines (B = 0.23, p = .04) contributed to the variance in salivary cortisol in addition to parental presence (B = -0.04 p = .04).

Conclusion: COVID-19-related visitation restrictions reduced NICU parent-infant interaction and may have increased infant stress. Low GA and central venous lines were associated with higher salivary cortisol. The interaction between immaturity, morbidity and parental presence was not within the scope of this study and merits further investigation.

Keywords: Cortisol; Covid-19; Neonatal intensive care unit; Premature; Skin-to-skin care; Stress.

Fig. 1

Timeline of the period with visitation restrictions at the two university hospital neonatal intensive care units.

Fig. 2

The included participants and the reasons for exclusion of 22 infants.

Fig. 3

Scatter diagram of the distribution of salivary cortisol values and parental presence in 72 infants. Each individual infant is marked by a coloured gestational age groups. The x-axis represents total parental presence (both during and after visitation restrictions) in hours average over three days in the neonatal intensive care unit. The y-axis represents log-transformed infant salivary cortisol in nmol/l.

Fig. 4

Panel A shows maternal and paternal presence in hours per day during (“yes”) and after (“no”) visitation restrictions. Panel B shows that when maternal and paternal presence in hours were added (green boxes), there was a difference during (“yes”) versus after (“no”) visitation restrictions. After the visitation restrictions (“no”), the two parents visited mostly together/at the same time, resulting in the time the infant had one or both parents present (blue boxes) was unchanged compared with the period with restrictions. Within each box, the horizontal black line represents the median value; boxes extend from the 25th to the 75th percentile; while the whiskers represent the minimum and maximum values, respectively.