As maternity leaves for Canadian women have increased, more mothers have met the six-month breastfeeding target recommended by public health officials, according to a new study.

The study, published Tuesday by the U.S. National Bureau of Economic Research, examined how the increase in maternity leave entitlements from six months to one year affected breastfeeding, and the health of mothers and their children.

Babies were breastfed by an average of one month longer after maternity leave benefits were extended to one year, a new study suggests.
(Canadian Press)

As of Jan. 1, 2001, job-protected maternity leave entitlements increased from six months to one year in most provinces.

The proportion of eligible mothers who breastfed exclusively for at least six months, as recommended by Health Canada and the World Health Organization, increased from 20 per cent to 28 per cent after the leave was extended, researchers found.

Breastfeeding was prolonged by an average of one month, said study authors Michael Baker, an economics professor at the University of Toronto, and economics Prof. Kevin Milligan of the University of British Columbia.

"For public health officials aiming to increase breastfeeding duration, it appears the labour market policy may prove an effective way of achieving breastfeeding goals," the researchers concluded.

Eligible mothers also returned to work three to 3½ months later after the policy change.

But it did not appear that women were more likely to start breastfeeding or attempt it as a result of extending leave, the researchers said.

No proof of improved short-term health

As for health benefits, there was no conclusive evidence that the increase in breastfeeding led to short-term improvements in the health of mothers or children up to 24 months.

The incidence of ear infections among babies 13 to 24 months old fell. But it's possible the decrease was not linked to breastfeeding itself, because maternal care was substituted for non-parental care such as day care, where children may be exposed to more viruses and bacteria.

There was also no evidence of breastfeeding helping or hindering weight during the expanded leave time, or affecting a child's overall health, based on reports from mothers who ranked their children's health on a five-point scale.

Work was the main reason mothers said they stopped breastfeeding, followed by mothers reporting that the baby was ready for solid food.

The study looked at all children born between 1998 and 2003 inclusively, except for births in Quebec, children from single-parent families (about 10 per cent of births) and cases where survey respondents were fathers rather than mothers.

Pediatricians recommend breastfeeding because the fluid meets a baby's nutritional needs, and contains antibodies that help babies fight disease and infections.

In 2005, the Canadian Pediatric Society shifted its guidelines to recommend breastfeeding newborns exclusively for the first six months, and continue breastfeeding for two years or more.