Postgraduate Profiles

Tash Sorensen

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Thesis: Normalising the circadian rhythm of preterm infants to improve immediate and long term health, developmental, psychological, metabolic and economic outcomes of preterm birth

The aim of this proposed PhD project will be to determine the pattern of postnatal circadian rhythm development in preterm infants and its dependence on gestation, as well as the effects that postnatal modulators/exposures may have during the time spent in the Neonatal Intensive Care Unit (NICU). Our main objective will be to develop an initial investigation used to obtain preliminary evidence to support an application for a clinical trial that evaluates a developmentally focused "circadian care package" on improving long term outcomes of preterm infants. Such a package would likely include simple adjustments to neonatal care practices. The package may suggest recommendations on timing of specific medications, and the use of simple ancillary items to normalise environmental and physiological circadian cues. Prior to developing the care package we need to understand how circadian rhythm develops in premature infants, what physiological cues are missing and what important environmental cues may disturb normal circadian development.

The long term goal for this project is to develop a interventional study across multiple medical institutions, proposing to benefit both nursing staff at the NICU and mothers of preterm infants.

Why my research is important

Circadian rhythms are critical to align physiology with environmental time cues (e.g. light/dark cycle) and are vital for optimal fetal growth and development. Neonatal circadian variation is an intrinsic component that develops during gestation. Fetal circadian development occurs through maternal circadian cues transmitted via the placenta by means of melatonin and cortisol.

Premature delivery removes the fetus from the usual maternal circadian cues that would otherwise regulate circadian development. Moreover, the more adverse consequences of circadian disruption are like to be exacerbated postnatally, by constant exposure to light and noise in the neonatal intensive care unit (NICU) as well as invasive procedures and pharmacological therapies that impact on wakefulness.

These "Circadian Care Packages" may be used to normalise the circadian rhythms of the preterm infants, which could improve immediate and long term health, developmental, psychological (both for mother and infant), metabolic and economic outcomes of preterm birth.


Mar 2016

Mar 2019