NZ blood test may reduce the risk of early births

Researchers targeting biomarker found in women whose babies were born too soon

New Zealand researchers are pioneering a new blood test for pregnant women that could potentially prevent babies being born too early. Preterm birth remains the leading cause of child death in almost all highincome and middle-income countries — and globally, more than one in 10 babies are born before 37 weeks’ gestation.

In New Zealand, the rate is around 8 per cent — and 14.6 per cent among Ma¯ori — and equates to some 5000 babies each year.

While the vast majority survive, they can carry a greater risk of problems with growth, learning, and adult diseases such as obesity and diabetes than babies born at term.

Efforts to tackle the risk have hit one major problem — about 60 per cent of these births happened without any warning, and often in women with no history of it.

There is still no way of reliably predicting whether a woman will go into labour prematurely. That may be about to change.

A team of researchers at the University of Auckland-based Liggins Institute and the University’s Faculty of Medical and Health Sciences has identified a unique molecular “fingerprint” in blood taken from women at 20 weeks of pregnancy who all went on to have their babies early, or at between 28 and 32 weeks.

The fingerprint was absent from blood taken from women at the same stage in pregnancy who went on to deliver at term.

In a new two-year programme, supported with a Royal Society Te Apa¯rangi fellowship, Liggins’ Professor Mark Vickers aimed to develop and validate the test in groups of women here, and in Australia and Ireland.

The potential biomarker revealed in the pilot study was derived from analysing what’s called micro-RNA, or miRNA.

MiRNAs are small non-coding RNA molecules that play key roles in the regulation of gene expression.

They’re also known to be involved in the development of, and protection from, a range of diseases.

Recent studies in this fastemerging field have highlighted the potential for miRNAs as biomarkers for osteoporosis, cancer and the pregnancy complication pre-eclampsia.

The research team lead by Vickers used state-of-the-art digital technology called NanoString, designed to count the number of individual miRNA molecules present in a maternal blood sample.

Much more sensitive and faster than other available methods, it demonstrated recent rapid advances in technology and medicine.

“If this test proves effective, it could potentially lead to much better outcomes for the babies and their mothers, both in the short and long term,” Vickers said.

“It could enable the targeting of existing and future therapies to delay or even prevent preterm birth.

“The platform could also be used to detect other pregnancy complications, such as gestational diabetes.”