Threatened pre-term labour occurs in many women during pregnancy and accounts for one third of all antenatal hospital admissions for pregnant women.  Fortunately most women who present with threatened pre-term labour do not progress to pre-term delivery; however, our ability to predict the 5% who will progress to delivery within 7-10 days is poor.  Each year in Australia more than 120,000 women are admitted to hospital with threatened pre-term labour, yet only 6000 of these deliver within 7-10 days. 

During 2004 and 2005, Dr Craig Pennell (Senior Lecturer in Maternal Fetal Medicine at the School of Women's and Infants’ Health, The University of Western Australia and the Women and Infants Research Foundation) in collaboration with Professor Stephen Lye and Professor Alan Bocking (Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto) have identified the genetic “signature” that identifies true pre-term labour in women who present with premature uterine contractions during pregnancy.

White blood cells share many markers with cells of the placenta and fetal membranes. In fact, many of the cells that make up the interface between the placenta and uterus are derived from the bone marrow similar to white blood cells.  The principle behind this research is similar to the concept of the “Canary in the Coal Mine”.  White blood cells pick up messages as they travel around the body. Our research group has shown that white blood cells can accurately pick up the genetic message associated with true pre-term labour earlier, and far more effectively than current clinical and diagnostic tests for true pre-term labour.

The genetic signature for “true” pre-term labour in maternal white blood cells that we have identified is capable of accurately predicting the timing of delivery in women who are admitted to hospital with premature contractions in 90% of the patients studied. This is far superior to the current techniques which have a 15% chance of predicting delivery within 48 hours. 

The success of this initial study has resulted in international funding from the March of Dimes Birth Defects Foundation and the PSI Foundation in Ontario Canada to evaluate the genetic signature for “true” pre-term labour in a larger population of women with threatened pre-term labour.  Further, the results of the first phase of this project have resulted in an application for a US patent.

The determination of the “genetic signature” for true pre-term labour is an exciting breakthrough in research into pre-term birth. The inability to accurately diagnose “true” pre-term labour leads to large numbers of women being hospitalized during pregnancy. In addition, it results in many women and their unborn babies being unnecessarily exposed to the potentially dangerous side effects associated with medications that attempt to inhibit labour and medications designed to promote maturation of the pre-term baby. Recent studies have suggested that the use of risk prediction strategies in women with threatened preterm labour may provide cost savings to the health care system.  It is therefore of critical importance to develop new noninvasive methods of accurately and reliably diagnosing true preterm labour which will provide the means to:

1) Effectively triage patients and so reduce demands on limited health care resources,
2) Limit the use of existing approaches (medication to promote maturation of the pre-term baby, medication to inhibit contractions and transfer to tertiary perinatal facilities) to those patients whose preterm birth is imminent and,
3) Define targeted patient groups to test new therapeutic approaches to prevent pre-term birth.