Everything and nothing will have changed for Meaghan Mikkelson when she pulls a Canadian jersey over her head Monday at the women's world hockey championship.

Reclaiming gold from the U.S. is still the goal. The Americans have beaten Canada in five of the last six world championship finals.

A pregnant Mikkelson watched her country's most recent defeat in 2015 from her Calgary home.

Six months after giving birth to Calder, the two-time Olympic gold medallist returns to the national team for the 2016 world championship in Kamloops, B.C.

The host team opens the preliminary round Monday against the defending champion U.S. at the Sandman Centre. Mikkelson will play her first international game for Canada since an overtime win over the U.S. for Olympic gold two years ago.

There's anecdotal and some scientific evidence indicating that increased red blood cells and a surge in hormones during pregnancy can make elite athletes stronger in the weeks after birth. Mikkelson will vouch for that theory.

"I'm shocked at how much stronger I am," the defenceman says. "It's pretty crazy and awesome.

"Somehow during my pregnancy and in the past two months I've gained a lot of muscle."

It's been a challenge

It's a compensatory perk for the hard work she's put in to re-gain her pre-pregnancy body and game. Getting to the gym and on the ice enough to be the world-class player you once were is not easy when you're a nursing mother.

"They say it takes a year for your body to go back to normal — whatever normal is I'm not sure — but it has been a challenge," Mikkelson said.

"Your ligaments and your joints are still kind of going through that transition and going back into place where they were before I guess you were carrying around a 30-pound medicine ball. That's been the biggest thing, just staying on top of little strains and pulls."

Her husband Scott Reid, a former minor pro goalie, coaches her Calgary Inferno club team which recently won the Clarkson Cup.

So when Mikkelson was cleared to play for the Inferno on Jan. 2, she and Scott were on the ice together for practices and games. Calder's grandparents or aunts stepped in as baby-wranglers.

"I don't think she expected it to be as difficult as it was," Reid said. "She's put a lot of work, dedication and time into it, whether it's parenting or on the ice. She's been able to find that balance."

Teammate to consult

Mikkelson has a former teammate to consult. Defenceman Becky Kellar returned to the national team to win Olympic gold in 2006 and 2010 after giving birth to sons.

"I knew Becky Kellar had been at a national-team camp just three months after she had her son," Mikkelson said. "I hoped for myself that setting a goal of being at our January camp four months after I had [Calder] was attainable.

"My body decided to co-operate."

The 31-year-old from St. Alberta, Alta., has played both forward and defence for Canada. She has 13 goals and 28 assists in 78 career games wearing in the Maple Leaf. In five world championships, she's worn a gold medal around her neck once in 2012.

"I'm sick of the silver medals," Mikkelson said. "I think I have kind of a newfound motivation after I've had [Calder] and what I've gone through to come back."

Scott and extended family are on Calder duty at Canada's training camp this week in Penticton, B.C., and during the world championship.

Nursing mothers were news at last month's Canadian curling championship in Grande Prairie, Alta., when there was initially no designated space in the arena for them. Organizers quickly found an area when the controversy started to pick up steam.

Mikkelson intends to nurse Calder when she can and will have a breast pump with her when she can't.

Calder, whose name Meaghan and Scott chose from a Twitter campaign, won't remember watching his mom play for Canada in Kamloops, but it will still become part of their family's history.

"To look back and tell him the story of this is what he did when he was so little, I had him and came back and played in a world championship in my home country and he was right there to watch," Mikkelson said.

"He may not know right now the impact that he has on me. Whether I have a good game or a bad game, I have this little guy to come home to and it puts things into perspective for you."