When pregnant women were trusted with $81 a month in prenatal benefits, no strings attached, their babies' physical health did better, say Manitoba researchers, who would like similar income supplements to be offered across Canada.

The Healthy Baby Prenatal Benefit offers support to families with a net household income of less than $32,000, on a sliding scale.

In Thursday's online issue of the journal Pediatrics, researchers say babies born to low-income women who received the benefit in 2003 to 2010 did better in terms of low birth weight and prematurity than a similar group born to low-income women who didn't.

"It actually adds to a growing body of evidence that if we raise the incomes, if we lift people out of poverty, the outcomes for infants and children are better than if we leave them in poverty," study author Marni Brownell, a professor in the department of community health sciences at the University of Manitoba, said in an interview.

While $10,000 was the average income for recipients in the study, Manitoba officials say the threshold to qualify for the full $81.41 per month is $21,744.

The unique aspect of this program was to offer money without strings attached, along with pamphlets about prenatal nutrition, breastfeeding and healthy infant development.

In contrast, many provinces and U.S. states offer conditional support for pregnant women, such as meal vouchers. The U.S. supplemental nutrition program showed mixed results for its association with better birth outcomes.

A leg up out of poverty

"Sending these women the money is a way of saying, 'We trust you to make good decisions,'" Brownell said. "We trust that you know what you need to have a healthy pregnancy rather than telling women you must spend the money on X, Y and Z."

When Lindsay Ladobruk's work contract ended following four miscarriages, she was put on bed rest while pregnant. Ladobruk said she was living on $150 a month before the supplement began.

"I was getting the $80 a month cheque, which was totally the difference of me eating or not, so that helped tremendously," Ladobruk said.

Her daughter, Aurora, is now a healthy four-month-old.

Among the nearly 14,600 pairs of mothers and newborns in the study, the researchers found reductions of 21 per cent for low birth weight and 17.5 per cent for preterm births.

The findings don't surprise Dr. Tatiana Freire-Lizama, an obstetrician at St. Michael's Hospital in Toronto who works with people living in poverty.

Relieving poverty even a little gives better outcomes, Freire-Lizama said.

"We know babies that are too small have trouble controlling their blood sugars, they have difficulty maintaining their temperature, they have difficulty feeding, and in the longer term we know that low birth weight has lasting impact on people's health," Freire-Lizama said.

In the long term, for instance, children who are born with low birth weight or preterm tend to have more difficulties in school.

The study was funded by the Canadian Institutes of Health Research and the Heart and Stroke Foundation of Canada.