Study: Maternal employment, breastfeeding and health

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Longer maternity leaves for Canadian mothers have meant that more of them have met breastfeeding targets recommended by public health agencies, according to a new study.

The study examined the impact that an increase in maternity leave entitlement had on time away from work, breastfeeding, and the health of both mothers and their children.

Women who gave birth before December 31, 2000 were typically entitled to a job-protected leave of six months. Those who gave birth after that date became entitled to one year in most provinces.

The study found that the extension has meant that more mothers returned to work later after giving birth and that they breastfed their infants exclusively for the recommended six months or longer.

It found that eligible mothers returned to work three to three and a half months later following the policy change and that breastfeeding was prolonged by an average of one month.

The proportion of eligible mothers who breastfed exclusively for at least six months – the duration recommended by the World Health Organization and Health Canada – increased from 20% pre-reform to 28% post-reform.

However, the study found that women are not more likely to start breastfeeding or attempt breastfeeding as a result of extended leave entitlements.

Extending leave entitlements have led to mothers breastfeeding longer, but the change did not appear to have affected the decision to initiate breastfeeding.

The study also examined whether the increased duration of breastfeeding led to improved health for infants and mothers. Data currently available limit the study of health benefits to children aged 0 to 24 months.

The study found no conclusive evidence that the increase in breastfeeding led to short-term improvements in the health of mothers or infants.

Ear infections were fewer but data suggest that this was due to a declining trend in ear infections rather than any induced increase in breastfeeding. There was no observed difference in the weight of children as a result of the increased duration of breastfeeding.

Data for the study were taken from the National Longitudinal Survey of Children and Youth (NLSCY) and the Canadian Community Health Survey.

Note: The sample from the NLSCY included all children born between 1998 and 2003 inclusively, with three exceptions: births in Quebec, children from single parent families (about 10% of births) and cases where survey respondents were fathers rather than mothers.

The study Maternal Employment, Breastfeeding and Health: Evidence from Maternity Leave Mandates has been published in English only by the National Bureau of Economic Research by Michael Baker, Professor and RBC Chair in Public and Economic Policy at the University of Toronto, and by Kevin Milligan, Assistant Professor of Economics at the University of British Columbia.

Definitions, data sources and methods: survey numbers, including related surveys, 3226 and 4450.

The study was conducted at Statistics Canada's Research Data Centres, a joint initiative involving Statistics Canada, the Social Science and Humanities Research Council, the Canadian Institute for Health Research and university consortiums.

For more information about the study, and to obtain a copy of the study, contact Michael Baker (416-978-4138), University of Toronto. For French media enquiries, contact Denis Gonthier (514-283-3282), Statistics Canada.