In this post, Rebecca Zosel reflects on the Louis Waller Lecture 2015 delivered by Professor Sarah Robertson, Director of The Robinson Research Institute at the University of Adelaide. Professor Robertson’s presentation, ‘Parenting begins before conception’, was based on a recent paper in Science[1]. The Lecture is held annually by VARTA to commemorate the significant contribution Emeritus Professor Waller has made to the regulation of assisted reproductive treatment in Victoria.
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Rebecca Zosel writes:
Professor Sarah Robertson delivered a fascinating lecture on preconception health, epigenetics and chronic disease during National Fertility Week 2015, which highlighted how the health of parents affects the health of their children and grandchildren. She explained that in addition to the genomic blueprint passed on by both parents at conception, parental exposure to a number of lifestyle and environmental factors in the months leading up to conception also play a role – through transgenerational epigenetic effects – in programming the development of the embryo and fetus, and ultimately the lifetime health of the child.
Sarah challenged the 100-strong audience to expand their view of the determinants of health, and explained how the health of mothers- and fathers-to-be sets the trajectory for the lifetime health of their children including their risk of developing chronic illnesses later in life.
Parents’ health affects the health of their children
Professor Robertson spoke of new discoveries in the field of epigenetics which have profound consequences and invoke the concept of ‘parenting before conception’.
Genes are sensitive to the environment and a number of external or environmental factors can switch genes on and off and affect how cells function. Changes in genes in response to the environment are called epigenetic effects and these can be passed from one generation to another during reproduction. For example, parental smoking and obesity and environmental toxins are all known culprits of epigenetic changes that have adverse health effects on offspring.
We have known for some time that epigenetic changes occur during pregnancy as the fetus responds to the environment in the uterus. For example, if a pregnant woman smokes or is under-nourished, this increases the risk of the baby being smaller than expected at birth, which in turn increases the risk of poorer health in adulthood.
We now know that the health of the parents before and at the time of conception also can have lasting effects on the expression of the genes and the lifetime health of the child, particularly their susceptibility to chronic diseases including heart disease, diabetes, allergy and asthma, and neurological conditions. “Things like the food that we eat, body weight, smoking, exposure to alcohol as well as various chemicals such as insecticides in the environment can have effects on our bodily functions, through epigenetic information that is transmitted from the parents into the child,” Professor Robertson said. Importantly, the health of both parents before conception plays a role – fathers are important too.
The time around conception is most critical
The reality of ‘parenting before conception’ and intergenerational effects hit home when listening to Kent Thornburg speak about nutrition flowing across generations. In his presentation, How we grow before we’re born matters: The epidemic of chronic disease and understanding epigenetics, Kent says:
“The egg that made me, was made in my mother’s ovary when she was a fetus in my grandmother. That means that the egg that made me was nourished by my grandmother. And that nourishment changed the way my risks for life will be. I was also nourished by my mother. So there’s a two generation effect on the nourishment.”
How incredible, but also a bit overwhelming when we think about the opportunities to intervene and improve health.
Which brings me back to Professor Robertson’s response to a question from the audience about how to quantify pre-conception health: How long before conception should prospective parents start thinking about their health? Professor Robertson clarified that the time of egg and sperm maturation and conception is the most critical. Males may focus on a 3-month period as this is how long it takes for sperm to mature. For females it is more complex, because eggs are present in the ovaries before birth. However, based on the fact that environmental exposures affect the way that eggs are selected and grow, Professor Robertson’s advice was to focus on optimising health in the months before trying to conceive.
Professor Robertson acknowledged the challenges of accessing reliable information about preconception health and the factors that can cause epigenetic changes, and commended initiatives like the national education program Your Fertility. The program provides evidence-based information on five key modifiable factors affecting fertility (age, weight, alcohol and tobacco use, and timing of intercourse).
Significant population health gains can be realised by improving the health of future parents, and these gains will flow across generations. In light of the strong evidence that parental influences begin before conception and affect the lifetime health of the child, strategies to achieve optimal parental preconception health should be considered within existing health policies and frameworks including those with a focus on chronic conditions, sexual and reproductive health, infertility, and health and wellbeing.
[1] Lane, M., R.L. Robker, and S.A. Robertson, Parenting from before conception. Science, 2014. 345(6198): p.756-760.
Rebecca Zosel is a consultant currently working with VARTA as Health Promotion Adviser. She tweets at @rzosel
