Transcript for Female Athletes Get Breast Reduction to Improve Performance
Reporter: International tennis player simoneseen here, playing at the u.S. Open. Has made headlines not for her serve. But for her decision to undergo breast reduction surgery. She went from a 34dd to this, a 34c. She caused a breakthrough where this wasn't a taboo topic. When you see people at the highest level, talking openly about these things, that opens the floodgates for other people to discuss it as a real issue. Reporter: Now, it's not just professional athletes going under the knife. It just felt uncomfortable for me because, you know, I had to wear two sports bras every time. Reporter: Carly mortensen decided to have her bust reduced surge surgically. I didn't know it with would be a bonus. And it would be worth it. Reporter:100,000 women had similar surgeries last year. Some of them, experts say, do it to play sports. We're starting to see a lot more young patients who realize there's a surgery out there that can help them and help them feel better. Reporter: But not all female athletes support the idea. Former south african volleyball star alina sherkova, a 34dd, criticized. Saying the surgery tells a message that well in doughed girls, quote, can't play sports. And that's just wrong. But does breast reduction enhance your game? She was suffering from severe back pain. After the surgery, she climbed 450 spots in world rankings. She's now ranked number 18. Now, carly is hoping the surgery will improve her performance on the field, as well. It's helped my play. Reporter: She's looking forward to this softball season, when she takes the field for her first official game. For "good morning america," reena ninan, abc news, new york. We're going to bring in abc news senior medical contributor, dr. Jennifer ashton with this. A lot of people are talking about it. You're very passionate. You have a wonderful daughter who is a great ice hockey player. What is your reaction? This is an example of where breasts have become global property. And people think they can weigh in and say whether it's right or wrong for a given woman. I don't care if she's an athlete or not. If she feels physically or emotionally bothered by the size of her breasts, she should have the prerogative to change that. Is it going to take someone from a medium-level athlete to an olympian? Probably not. But will it enhance performance in any way? I have patients who are elite tennis players, swimmers, who will say, absolutely. Their breast size changes by a minimal amount, they notice a difference. We have to be careful by setting up a double-standard. And lpga, with the followthrough. And ronnie lott can cut off a finger if it helps his performance. But if you talk about a woman, we have a double-standard here. We want the women to be jocks and athletes. If they need to do something to change that, we have a problem. Medically, the pros and cons. So important. Breast change throughout the course of a woman's lifetime. By 20, they still might not be finished growing. If you get this done too early, potentially it might not really be doing what you want it to do. Usually, it doesn't interfere with breast-feeding down the road. It shouldn't be taken lightly. It's up to the individual woman. In twitter, my twitter is blowing up with split reaction. Most interesting, men, very against this. The women are saying, it's a woman's choice, let her do what she wants. The men are against it?
This transcript has been automatically generated and may not be 100% accurate.