NEW YORK - Back in 2007, United States women's soccer team midfielder Shannon Boxx found out she had lupus.

Despite occasional bouts of extreme fatigue, joint pain and swelling associated with the disease, Boxx went on to represent the United States at the 2007 and 2011 FIFA Women's World Cup and won gold medals at the 2008 and 2012 Olympics.

Like most athletes, Boxx has had to overcome severe injuries that required rehabilitation.

Still, of all the challenges she's overcome to play at a world-class level for 13 years, Boxx said nothing was more difficult than returning to make the 2015 World Cup team after giving birth to her daughter, Zoe, in 2014.

"It was harder than I thought it would be," said Boxx, who turns 38 later this month. "The amount of hormones going through you, the changes to your body, not being able to sleep much because you have an infant to care for, I think all of that stuff comes into effect.

"The team has a great training staff and the physical therapist helped me, but the journey was a lot longer than I anticipated."

Boxx is one of three mothers on the United States World Cup squad.

Team captain Christie Rampone, 40 later this month, has daughters - 9-year-old Rylie and 5-year-old Reece.

Forward Amy Rodriguez, 28, had her son, Ryan, in 2013.

"It's great for the obvious reasons," Rampone said, "but one of the other things is that [being a mom] has put soccer into perspective for me.

"You don't focus completely on every little mistake or thing going on in training. I get to cross that line of playing a sport I truly love and am passionate about but then at home I get to be with the kids.

"Being away from the game while you are pregnant makes you want to return even more."

Becoming a father is not that much of a life-altering experience for a high-level athlete. Except for some paternal leave when the baby is born, it's business as usual for most male athletes.

Female athletes, in contrast, literally have to consider whether they want to risk their career by having a baby while they are at the top of their profession.

Obviously, there are numerous examples of women athletes returning to the highest level of competition after childbirth, but there is no guarantee.

Rodriguez, who is 5-4 and depends on her speed as an attacker, put on 30 pounds during her pregnancy. She was away from the national team for a year. She only had months to prove that she was physically ready to a spot on the roster.

"For 9 months I was carrying a child and my weight was distributed totally differently," Rodriguez said. "It took a while to get my speed and right balance back."

Most of the people associated with women's sports know that the possibility of star players getting pregnant is something to be anticipated. Still, a World Cup is a World Cup, and in the end, a coach takes the best players at that time.

"There is the professional piece and then there is life," USA coach Jill Ellis said. "For me, I would never not be supportive of a player who makes that kind of decision.

"What I do know is that when these women go into making that decision and then want to continue playing, what I see is character, work ethic, determination and resolve. It is the character of the women who make up our soccer team. They get on with it, plain and simple."

Boxx said having a child brought balance to her life that has helped make her a better player.

"I was one of those players who would go to my room and stew over every little thing that went wrong," Boxx said. "Zoe is the best thing that's ever happened to me.

"I can have a bad day and then go home and have her running to me when she hears my voice, and then all the bad stuff disappears. I get to bring two things that I love together."

Rampone said one of the messages of women's sports is empowerment and encouragement for girls to pursue their dreams. She said her daughters growing up with a dozen soccer aunts who are the essence of that message is a valuable learning tool that they have gotten to experience firsthand.

"My daughters are learning that anything is possible," she said. "You just have to keep working at it and pushing for it.

"Mommy wanted to continue to play soccer and wanted to have a family. I've been able to do both."

Boxx said her path of being a "soccer mom" would be a lesson for her daughter as well.

"When she gets older, I can show her what I did and how she was there to see it," Boxx said. "I'll tell her my journey coming back from having a baby, or knee surgery or lupus was not easy, but I was able to do it.

"I loved the game and I worked hard to keep it. She's going to know what kind of things she can do for herself."