Salivary cortisol in late preterm infants

A Preliminary Study of Correlates of Premature Birth and Their Influence on Cortisol Levels in Young Children

OBJECTIVE

The HPA-axis is programmed during early infancy, but a lot is unknown about the programming of the HPA-axis in prematurely born or small for gestational age (SGA) children. Therefore, the aim of this preliminary study was to investigate the influence of prematurity and variables associated with birth on cortisol levels in young children.

METHODS

Cortisol was measured in a cross-sectional design in 38 premature born participants (<37 weeks of gestation), aged between 3 - 9 years old. Correlates of prematurity (degree of prematurity and birth delivery route) were investigated in relationship with cortisol levels with regression analysis.

RESULTS

Corrected for sex, delivery by C-section was associated with lower cortisol levels in the children (ß = -.42, p = .028), with an explained variance of 34%.

CONCLUSION

Birth delivery route by C-section is associated with lowered (or flattened) cortisol levels in children born prematurely. This is clinically relevant and might have important implications, because an HPA-axis disturbance might lead to developmental problems later on in life. However, future research is necessary to investigate the underlying indications for performing a C-section, which will help to understand factors that influence the HPA-axis development in children born prematurely.

Benefits of Kangaroo Mother Care on the Physiological Stress Parameters of Preterm Infants and Mothers in Neonatal Intensive Care

It is well documented that the stress of separation of mother and baby can lead to short-term physiological instability as well as neurological, sociological or psychological consequences that may last a lifetime. Objective: The goal was to estimate the effect of kangaroo mother care (KMC) on physiological and biochemical parameters of preterm infant stress and maternal stress in neonatal intensive care. Methods: The investigation involved 112 preterm infants. Two groups were compared according to the mean duration of KMC during 12 days of study: the KMC group (mean duration more than 90 min daily) and the control group (less than 90 min). Results: Kangaroo mother care for more than 90 min on average per day in preterm infants is associated 12 days after the intervention with lower mean cortisol levels (p = 0.02), greater weight gain and less need for parenteral nutrition in preterm infants, as well as less postpartum depression (p = 0.02) and lower cortisol levels (p = 0.002) in the mothers of preterm infants. Conclusions: This study suggests that KMC can be used to improve the stress of preterm infants and their mothers, and that the greater weight gain observed in these preterm infants could contribute to a shorter average hospital stay and lower healthcare expenditure.