Queen's University researchers have found giving nitroglycerin to women in premature labour greatly improves their baby's health.

Dr. Graeme Smith, principal investigator in the study, says that using a nitro patch on pregnant women helps to prolong pregnancy and improves the baby's condition with fewer side effects than medication commonly used to stop premature labour.

"It's very exciting. The results were stronger than we anticipated," Dr. Smith told CTV News.

The nitroglycerin patch is commonly used to calm the heart of patients with angina.

During the trials, the patch was placed on the woman's skin while she was having contractions. Researchers found that the uterus, which is also a muscle, relaxed and that blood flow to the placenta was increased, causing pregnancy to be prolonged for up to three weeks.

The patch also reduced the risk of complications, such as lung disease and brain injuries, and the risk of infant deaths.

"This is a significant improvement in outcome. It reduced the chance of having a major complication by 70 per cent," Smith said.

The five-year randomized trial recruited 153 women at the time they went into pre-term labour.

The improvement is the most significant for babies who are going to be born very early; between 24 nad 28 weeks.

Reducing fragility and complications with infants means greater relief at neonatal units in Canada.

"Less time on a ventilator, less complications, less time on oxygen, less time in the hospital," Dr. Michael Flavin, a neonatologist, told CTV News.

Kelly Young is one expectant mother who was administered the patch when she went into labour early. The treatment was successful, and she is hopeful her baby will carry to term.

"I am due April 15 and I am hoping the baby will stay there until April 15," Young said.

Nearly 6,000 babies are born premature in this country. It is estimated that it cost the Canadian health system $2 billion a year to take care of premature babies and their medical complications.

The incident of premature birth is the leading cause of death and disability among babies worldwide.

Approximately 7.5 per cent of all babies in Canada are born prematurely (before 37 weeks) and 1 to 2 per cent are born before 34 weeks.

Premature births can lead to other more prolonged complications, such as learning disabilities and breathing difficulties.

The study was organized by the Queen's Perinatal Research Unit at Kingston General Hospital, with data management by the Ottawa Maternal Neonatal Investigators at the Ottawa Health Research Institute.

With files from CTV's medical specialist Avis Favaro and medical producer Elizabeth St. Philip