Discovery May Bring Special Treatment For Premature Male Babies

This finding may explain why male babies born prematurely are twice as likely to die as female babies in the first 72 hours of life. It could also lead to new ways of treating premature babies throughout the world.

Researchers from Hunter New England Health and the University of Newcastle, in collaboration with the Hunter Medical Research Institute's Pregnancy and Reproduction Research Program, completed two studies, looking at babies born at 24 weeks to full term.

"This is the first time that the small blood vessels (microvasculature) have been extensively studied in a large group of premature babies," said Dr Ian Wright, a Neonatologist at Hunter New England Health's Kaleidoscope Neonatal Intensive Care Unit.

"We discovered that changes in small blood vessels are linked with how sick the babies are after birth. Babies who had low blood pressure and were more ill were unable to control the blood flow in their small blood vessels. This was less of a problem as babies got older or if they were born more mature.

"We showed that there is a sex difference, with the girls able to regulate the small blood vessel flow, and boys unable to control it. Again, this difference resolved with time or was less of a problem in the more mature infants.

"The finding suggests that doctors may need to trial different approaches to treating baby boys, born prematurely, than baby girls. Earlier or more support for the circulation could be used in boys because they are at greater risk of severe problems. Further research will address these approaches."

These findings were published in the journals Archives of Disease in Childhood, Fetal and Neonatal Edition and Pediatric Research. Infant mortality remains the most common cause of childhood death. Premature birth is the main cause of infant mortality and infant disability. In Australia, premature birth occurs in more than 17,000 pregnancies each year.

HMRI is a partnership between Hunter New England Health, the University of Newcastle and the community.