Quick Dips

Preventing Premature Births

Professor Murray Mitchell has a vision -- a world where all babies are born healthy and the problem of pre-term delivery is a thing of the past.

Mitchell, the head of the Department of Pharmacology and Clinical Pharmacology at the University of Auckland School of Medicine, believes the best way to do that is to deliver them at term. That's why he and his team are researching the importance of cytokines -- chemicals released in response to infection -- which modulate the production of prostaglandins in pregnancy. His team has just been funded by the Health Research Council to develop a model of infection-associated pre-term delivery.

Prostaglandins are small lipids (fats) made by every tissue in the body and are particularly important in reproduction. They are the key to menstruation and ovulation and regulate the onset of labour. Clinically they are used to induce labour by making the uterus contract, and they also soften the cervix to allow the baby to be delivered more easily.

Prematurity is an underestimated but major health problem both here and overseas. Pre-term labour occurs in 10% of New Zealand births, and accounts for three-quarters of all perinatal mortality and morbidity. Children born prematurely are much more likely to experience a variety of ongoing health problems.

"The emotional impact of premature death or resultant disability is enormous," says Mitchell. "Economically it's devastating. We believe that if we can find out how to safely stop prostaglandin production in the uterus, we can prevent pre-term labour."

Significantly more funding is given to research on prematurity in the US. When Jackie Kennedy lost a child in premature labour while her husband was President, research into its causes and prevention was given top priority.

A major cause of pre-term labour is intra-uterine infection, to which the host responds by producing a "cascade" of cytokines. Mitchell's team is evaluating the critical steps in that process, trying to find out which step can be switched off and would then be possible points for clinical intervention.

Recently, Mitchell and collaborators in Utah discovered that the natural cytokine interleukin 10 (IL-10), will block the prostaglandin-cytokine cascade and stop infection-driven premature labour in mice. He regards this finding as very important. Developing and extending this animal model, the Auckland team is conducting in vitro tests on tissues from human pregnancies to test for any potential side effects of IL-10.

Mitchell came here two years ago from the University of Utah where he headed the research division of the department of obstetrics and gynaecology. He says that New Zealand scientists have played a major role in reproductive research, out of proportion to the size of the country and resources available. It was the reputation of New Zealanders such as Sir Graham "Mont" Liggins, a world leader in studies on the mechanisms of the onset of labour, and the late Geoffrey Thorburn, an Australian, which attracted him here.

"There were bigger opportunities elsewhere, but the commitment to high quality research here was more attractive," he says.

Pamela Fleming, Auckland University School of Medicine