Claims that exercise while expecting might boost brain development

We’ve come a long way from the days when obstetricians advised women to take it easy during pregnancy.  Today, healthy expecting mothers are encouraged to stay active for reasons ranging from decreased back pain and sleep problems to easier post-partum recovery and reduced risk of child obesity.  Now there is preliminary research to suggest that exercising during pregnancy might even give your child’s brain a jump-start on development.

As reported at last week’s Society for Neuroscience (SfN) annual conference, researchers from the University of Montreal randomly assigned women at the start of their second trimester to either an exercise or a sedentary group.  Women in the exercise group were told to perform at least 20 minutes of aerobic exercise three times a week at a moderate intensity.  Although, the study abstract notes that women in this group went well beyond the 60-minute per week minimum and exercised an average of 117 minutes each week.

A mere 8 to 12 days after delivery, researchers invited all mothers and their newborns back to the lab. Babies were fitted with specialized caps made up of soft electrodes that detect electrical activity in the brain (a tool called electroencephalography (EEG)). Scientists waited for the newborns to fall asleep on their mother’s lap and then monitored how their unconscious brains responded to both familiar and novel sounds – a proxy for auditory memory.

“This is important to look at at this stage in their development, because the ability to discriminate sounds is the basis of learning to speak and to understand the sounds around you,” notes Elise Labonte-LeMoyne from the research team.

The researchers reported that the babies whose mothers had exercised exhibited more mature patterns of cerebral activation. They also suggested that this could indicate their brains are developing more rapidly. The study’s lead researcher, Dr. Dave Ellemberg said in a statement, “We are optimistic that this will encourage women to change their health habits, given that the simple act of exercising during pregnancy could make a difference for their child’s future.”

Before the media gets ahold of this news and conveys the message to expecting mothers that they can exercise their unborn children straight to the Ivy Leagues (woops, too late!), there are some important limitations to emphasize about this initial research. Although the findings were presented at the reputable Society for Neuroscience’s (SfN’s) annual meeting, the methods and findings have not yet undergone the rigors of a peer-review, and have not yet been published in a journal.

Hence, it’s difficult to really assess the quality of this work, as well as its generalizability.  Among other things, we know little about how scientists monitored or determined exercise intensity in the exercise group. It’s also not clear how sedentary the “sedentary” group really was. Did the women exercise up until delivery? We’re not sure of that either. Also, the only report that I saw on the sample size indicates that only 18 women participated.  It’s a start, but hardly conclusive.

Finally, long-term conclusions about the capability of a person’s brain can hardly be drawn based on the results from a single test of auditory memory that is given less than two weeks after entering the world.  To see if the benefits of prenatal exercise do have any lasting effects, Dr. Ellemberg and his colleagues plan to track the infants’ cognitive, motor, and language development until they are at least 1 year old.  I look forward to seeing those published results!

While these exercise findings are both novel and encouraging, they should – as with any science – be interpreted with caution.

[Here’s a nice video from the University of Montreal’s kinesiology lab group for anyone who speaks French 🙂 or might be interested in some visual footage of the study’s methods].