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Preconception health care matters when it comes to childhood health – U of T led study

24 February 2023

We know that a person’s health during pregnancy impacts their child’s developmental trajectories, but what about parental health before conception?

A new study led by Professor Cindy-Lee Dennis of the Lawrence Bloomberg Faculty of Nursing and published in BMJ Family Medicine and Community Health has found that a significant number of Canadian women have poor preconception health or interconception health. Interconception health refers to the period between two pregnancies which for most women, spans 24 to 36 months.

According to the study, 55 per cent of women had poor preconception health with four or more health risk factors including a high body mass index, poor nutrition or diet, low physical activity, and poor mental health with over, 30 per cent of those surveyed indicating a high level of loneliness. It was also found that those with four or more of these risk factors were more likely to have a lower level of education or were born outside of Canada. For Dennis and her team, this signifies that there is a great opportunity to target a public health and primary care response at the population level to improve preconception health.

Profile of Cindy-Lee Dennis

“What happens in utero can have a significant impact on a child’s health and well-being that continues into adulthood,” says Dennis, (pictured right), who is also a senior scientist at Lunenfeld-Tanenbaum Research Institute at Sinai Health. “There is now a growing body of evidence that suggests the health of parents prior to pregnancy is an important predictor of the long-term health of the child.”

Of women surveyed in the current study, Dennis points out that over 44 percent were classified as having a BMI over 30 which would categorize them as obese according to WHO criteria. Women who have a BMI greater than 25, are not only at risk for more severe pregnancy complications but meta-analytic data suggests it is also a significant risk factor for childhood obesity. The percentage of men with a BMI >25 was even higher than women.

“These are considerable intergenerational health risks that we should not be ignoring,” says Dennis. “Today, preconception care is not readily delivered by health care providers because most women do not seek care until they are well into their first trimester.”

In Ontario, the current standard of practice is for public health to provide preconception health care, and a screening tool to identify a patient’s preconception health risks, is available for physicians. However, with over 50 per cent of pregnancies in Canada being unplanned, and women not seeking care in their first trimester when important fetal development is occurring, there is a significant need to address preconception health risks with a more targeted approach.

“The good news,” Dennis says, “is that most of the common preconception risk factors identified in our study are modifiable and there is an opportunity for greater public awareness campaigns to educate individuals in their reproductive years about how these health behaviours can place not only parents but their future children at risk.”

Therefore, family level interventions that focus on improving health behaviours such as adopting a healthy diet and becoming more physically active, in addition to supporting positive mental health and reducing alcohol or cannabis use is something that at a policy level, needs to be considered.

“Children mimic the behaviours of their parents,” says Dennis. “By setting up parents to consider their own health before conception or just leading healthier lives, will go a long way in changing the future health of generations to come.”

This particular study is part of the The Healthy Life Trajectories Initiative (HeLTI) that was developed in partnership with funders from Canada, India, China and South Africa and in collaboration with the World Health Organization to address the increasing burden of non-communicable diseases – including obesity, diabetes, cardiovascular disease and poor mental health – around the world. There are four separate but harmonized randomized controlled trials being implemented in Soweto, Mysore, Shanghai, and all across Canada. All studies are focused on developing evidence-based interventions that span from preconception across pregnancy and into the postnatal and early childhood period, with the goal of improving maternal, paternal, and infant health, and ultimately the life-long well-being of the child.

If you or someone you know is planning a baby in the next 3 years, please consider joining the HeLTI Canada trial. For more information check out