27 June 2011
Babies born prematurely could be at greater risk of developing kidney diseases later in life according to a landmark study investigating the impacts of preterm birth on kidney development.
The Monash University study is identifying new strategies for minimising the adverse consequences to the kidney of being born preterm, which accounts for around eight per cent of births each year in Australia.
By comparing the kidneys of babies born prematurely with those growing normally within the womb, the research team, led by Associate Professor Jane Black from the Department of Anatomy and Developmental Biology, identified that preterm babies often had abnormalities in their nephrons – the ‘filtering units’ of the kidneys.
“An average person has around 900,000 nephrons and the number we have at birth is the number we have for life,” Associate Professor Black said.
“The majority of nephrons are formed in the last trimester of pregnancy at a time when preterm infants are already delivered. We have shown that babies born preterm do continue to grow nephrons after birth. However, in some babies up to 13% of the nephrons are abnormal and unlikely to ever be functional. So these babies will start life with a reduced number of functional nephrons.”
Associate Professor Black said the findings were of critical importance because of the known link between having fewer nephrons and the development of hypertension and kidney diseases in adulthood.
“Our findings indicate that preterm babies could be much more susceptible to renal disease later in life,” Associate Professor Black said.
“Particularly in the last 30 years, we have had great successes with preterm births and today even babies born 26 weeks premature have an 80 per cent chance of survival. Preterm babies now account for around eight per cent of births in Australia and 12-14 per cent in the USA.
“Because the improvements in survival rates of extremely preterm infants are only relatively recent, we have not yet witnessed the impact on the health system as individuals born prematurely progress into adulthood.”
Associate Professor Black has received two prestigious grants from the National Health and Medical Research Council (NHMRC) administered by Monash University.
“The NHMRC funding will enable Monash researchers to study the development of kidneys and hearts in preterm babies,” Associate Professor Black said.
“With the kidney studies, our aim is to develop strategies that will ensure these babies have the highest number of functional nephrons possible, in order to give them the best start in life.
“We need to know what impairs nephron development and are looking at a range of possibilities, including the factors that cause preterm birth, medications taken during pregnancy, and care following birth.
“We are also undertaking studies of kidney function in preterm babies at the Royal Darwin Hospital so we can investigate the renal development of both Indigenous and non-Indigenous babies. This is timely as Indigenous people have 17 times greater incidence of renal disease than the non-Indigenous population,” said Associate Professor Black.