As the U.S. presidential election continues to take shape south of the border, new research reveals how Ontario was impacted by Donald Trump's presidential victory in 2016.

The win led to a brief decline in the number of boys born in Ontario, according to a study led by Dr. Ravi Retnakaran, an endocrinologist at Mount Sinai Hospital in Toronto. It was published Monday in BMJ Open, a British medical journal.

The study showed that unexpected election results had a similar effect on birth sex ratio that researchers commonly see in disasters such as terrorist attacks, said Retnakaran. This was seen in liberal-leaning ridings, where Trump's win may have been seen as a societal stressor, he said.

It was a feeling of "surprise, shock and some apprehension about the future" that led Retnakaran to wonder whether Trump's surprising win would follow this birth ratio trend.

He and a team of Canadian researchers analyzed data on all births in the province during three periods of time: before the election, from April 2010 to October 2016, shortly afterwards, from November 2016 to February 2017, and later on, from March to October 2017.

Dr. Ravi Retnakaran wondered if the presidential victory would have an impact on sex ratio, after feeling a sense of surprise, shock, and apprehension about the future in Toronto. (Submitted by Dr. Ravi Retnakaran)

The data showed that the lowest ratio of boys to girls born in the 12 months after the election happened in March 2017. That's exactly within the three to five month window that the sex ratio would change after an adverse societal event, said Retnakaran.

"Then, in the five months from March to July, you saw the recovery of the sex ratio," he said.

But not everyone in Ontario considered the unexpected victory of the right wing Republican nominee to be highly stressful.

When researchers further analyzed the data, they found there were only fewer boys born in Liberal-leaning areas.

"The liberal leaning parts of the province are more likely to perceive the outcome of the election, the unexpected outcome, as an adverse societal stressor. The conservative leaning parts of the province were less likely to perceive it as such."

'Highly unlikely' upcoming presidential election will have same impact

So why does an adverse society event impact the number of boys that are born?

At the point of conception, the sex ratio is considered to be a 50/50 split said Retnakaran.

"The concept of an adverse societal event is believed to be affecting women who are within a particular window, about 20-25 weeks gestation at the time of the adverse event … for women who are in that window, there's a greater chance they're going to lose a male baby than a female baby."

Retnakaran believes further research is needed in order to understand why a societal stressor at a particular time during the pregnancy is more likely to cause the loss of a male baby over a female one.

He also said it's "highly unlikely" that the upcoming 2020 presidential election has a similar impact on birth sex ratios in Ontario.

"Who knows that's going to happen in the 2020 election. But regardless of what happens, I find it hard to anticipate that it's going to be as surprising an outcome to people as the 2016 one was, regardless of a person's political affiliation."